The church conducted three services a day, seven days a week, for over 3 years!  Thousands of seekers received the "tongues" baptism, including many Molokans. Years later many Pentecostal "revivals" were conducted in tent meetings on Oake's lot in the Flat's. English speaking Molokans often translated. Oake's lot is now Pecan Playground, at First and Pecan Streets.

The article Samarin challanges was updated in a history of the church's founder: (Christian History. Winter 2000, Vol. XIX, No. 1, Page 17) PENTECOSTALISM: William Seymour. The author places Seymour’s impact on American religion ahead of Martin Luther King, Jr.  [NOTE: Originally this article was posted to be viewed for free, now they charge.] Check the links at the bottom of the article, particularly "Azusa Street" which posts all their original newspapers. 

I first learned of this church in 1995 from a former President of the UMCA, Paul Kosareff, who left the Molokan faith to join the Pentecosts. A few years ago Paul sent me a large envelope with copies of old news clipppings, most of which you can now read on the web. I didn't understand the significance of these articles until I decided to examine the origin of George's complaint and connected the two.

In Molokans in America (pages 101-102, end of chapter 5), John K. Berokoff reports about  the Molokan leader Philip Mikhailovich Shubin and the Pentecosts:

Also see the previous report: Mission to convert Los Angeles Molokans to Orthodoxy failed in 1930s.

I find more evidence on the web of connections between the Azusa Street Revival and the Molokans. Thanks to their newspaper, The Apostolic Faith, which was distribute free to 50,000 subscribers, when the population of Los Angeles was 250,000. Surely every Molokan in Flat's knew about this church and saw this free paper, especially since it reported about the them in the first issue, and the church was within walking distance.

1906 September — The Apostolic Faith (Volume 1 Number 1)  [Only the first page is posted now] — The first edition of the newspaper appears to report that Apostolic Faith Mission members spoke at a Molokan church in the Flats, then invited the Molokans to attend their church, which many did with a translator: 

"[Jumper] RUSSIANS HEAR IN THEIR OWN TONGUE".
"Different nationalities are now hearing the Gospel in their own "tongue wherein they were born." Sister Anna Hall spoke to the Russians in their church in Los Angeles, in their own language as the Spirit gave utterance. They were so glad to hear the truth that they wept and even kissed her hands. They are a very simple, pure, and hungry people for the full Gospel. The other night, as a company of Russians were present in the meeting, Bro. Lee, a converted Catholic, was permitted to speak their language. As he spoke and sang, one of the Russians came up and embraced him. It was a holy sight, and the Spirit fell upon the Russians, as well as on others, and they glorified God."

1907 April  — The Apostolic Faith (Volume 1 Number 7) — The 7th edition reports about the Russian and Armenian Molokans in the Flats: "Russians and Armenians in Los Angeles are seeking the baptism. The Armenians have a Pentecostal cottage meeting on Victor street, between 4th and 5th. [Now under the I-5 Freeway.] Some have been baptized with the Holy Ghost."

Here's comentary  from an American-born Armenian Molokan-Jumper historian, Joyce Bivin:

We have a similar story in our community about the Azusa Street Revival. The story goes like this — quoted from a letter by M. Mushagian:

"Our people came to Los Angeles right after the Azusa Street Revival. They used to attend the meetings even though they didn't understand the American language. They saw that the Holy Spirit was moving there like it did in the Old Country. So they accepted Pentecostal because they believed in Acts 2:4."

There's really no reason to discuss who started speaking in tongues first. This manifestation of the Holy Spirit has been going on throughout the centuries since it was promised by Jesus and began (in Jerusalem, by the way!) with the Apostles 50 days after the Resurrection/Passover. It wasn't a movement as such until the Azusa Street revival.

The Armenians [Molokan-Jumpers] apparently were worshipping in this manner, including dancing in the Spirit, (jumping, which my grandmother did at one of the Paskha meetings and the next day mother told me she was healed of whatever affliction she had at the time), prophesying, speaking in tongues, etc. before they came to America. I wasn't aware the [other] Molokans responded to the Azusa Street meetings [like the Armenian Molokans]. After the Armenians visited the Azusa Street meetings, they eventually changed their identity from Armenian Molokans to Armenian Pentecostals. Though they kept the Molokan traditions in their worship, their theology shifted from focusing on Jesus and M.G.Rudomitkin (whose book was next to the Bible on the table) to Jesus's teachings as defined by Pentecostal/Protestant doctrine.

The first place our people gathered to worship was on Boston Street. The next place was on 431 S. Pecan Terrace, in a large room where my great grandfather eventually turned into a bath house. Then they moved to Gless Street [all in the Flats] and next to Goodrich Blvd [in East LA near Atlantic] before moving to Hacienda Heights. The [Armenina-Molokan] church today is located in Hacienda Heights, off Hacienda Blvd. on West. It's the first entrance on the right after you turn on West.

They've removed "Armenian" from the name of the church to make it more neighborhood — friendly. They sing a couple of the old songs [Psalms, verses] right in the beginning of the service before continuing with the American choruses and hymns. They still observe all the Feasts [of the Maksimisti/Jumpers]. Mrgditch Perumean's grandson, Stanley is the leader. 

We learn that Molokans often attended the nearby Mission, and that Mission members often visited and documented the nearby Molokans. With 3 services a day everyday, it was convenient for any Molokan working or shopping downtown to drop in. The irony of these reports is that the Azusa Street Mission is credited by Penetecostals and some religious historians with introducing the Holy Spirit to Russia:

The Origins of the Pentecostal Movement, by Vinson Synan, Ph.D. — Holy Spirit Research Center, Oral Robert University — "Soon ... the movement reached the Slavic world through the ministry of a Russian-born Baptist pastor, Ivan Voronaev who received the pentecostal experience in New York City in 1919. Through prophecies, he was led to take his family with him to Odessa in the Ukraine in 1922 where he established the first Pentecostal church in the Soviet Union. Although he was arrested, imprisoned and martyred in a communist prison in 1943, Voronaev's churches survived incredible persecution to become a major religious force in Russia and the former Soviet Union by 1993."

Though speaking in tongues is documented in America before the Molokans arrived — North Carolina 1896 and 1901 in Kansas — the Azusa Street Revival is considered to be "the birth of modern Pentecostalism".

American Molokan Jumper oral history (documented in the Book of the Sun) reports that Jumpers recieved the "outpouring of the Holy Spirit" in the Milky Waters region (now in Ukraine) in 1933. 

Some questions: 
A. Who spoke in tongues first in LA, Jumpers or Pentecosts?
B. Did the Jumpers teach speaking in tongues to the Petecostals?
C. Did the Azusa Street Mission teach the Jumpers? 
D. Did the Jumpers meet people like themselves with whom they shared in the glory of the Lord and they learned a little from each other--like raising hands and jumping?
E. What percentage of Jumpers joined the Pentecosts due to these close encounters in the new country?

Don't everybody jump into this discussion at once.  :-)