The Melodiya enigma

Can anybody solve this enigma?
Kondrashin recorded Myaskovsky's 6th Symphony, Op. 23, at least 2 times. The first, released by Russian Disc, and recorded in 1959, has been the only known for many years. Today it is almost impossible to find it (The Russian Disc label had problems with another great Russian musician: this is anoter story). Then Melodiya issued another one (MEL 10 00841), splendid, of a kind of magnetic strength, in 2005. The sound quality, fabulous (though it is obviously a live), suggests a later version than the Russian Disc's, and the timings are slightly different. If the chorus is the same, the excellent ensemble prepared by Yurlov, that very often worked with Kondrashin (for instance, it was invariably with this chorus that he performed and recorded the Babi Yar Symphony by Shostakovich), in 1959 Kondrashin conducted the USSR State Symphony Orchestra, whereas the new disc features a fantastic Moscow Philharmony.
I'm not suggesting that the 1959 version is not interesting. Not in the slightest bit! Granted the poor sound quality, it is a thrilling version, and the USSR State Symphony Orchestra can be proud of having made such fabulous recordings as this one, alongside with the magnificent 5th Symphony by Mahler, or the complete Symphonies by Brahms.
But the Russian Disc version cannot compete with the Melodiya one, because of the recording quality, and because of a superior involvement, the few changes made by Kondrashin beeing undoubtedly excellent: many passages are read with a superior sense of urgency, like, before the chorus intervention, in the last movement, the reexposition of the theme of the 1st movement by the tubas, now quicker and more sinister.
Where does this recording come from? You always have to be careful with a conductor whose recording legacy comes from broadcastings for more than a half of it. There, it seems it is the case. The label Melodiya dates it from December 5, 1978. So, that's a new item we can add to the official discography, thanks God, and thanks to Melodiya.
Then, if you read the jacket of the magnificent Tahra album (501-502) released in 2003 (Berlioz, Schubert, Franck, Sibelius, 4 previously unpublished items), you may have a strange feeling. You will read:
"On Sunday, December 3 1978, Kirill Kondrashin - accompanied by his interpreter and future partner in life Nolda Broekstra - turned up on the doorstep of Piet Heuwekemeijer, former managing director of the Concertgebouw Orchestra. Kondrashin had decided for personal and artistic reasons to seek asylum in Holland and he knew of Heuwekemeijer's experience in arranging residence permits for Eastern European musicians [a note gives a bibliographical reference to Heuwekemeijer's autobiography]. Together they went to a police station in Amsterdam, where the police took away Kondrashin's shoelaces and tie and locked him up in a cell. He eventually got his residence permit and the Concertgebouw Orchestra did everything in its power to provide the welcome guest with a more settled position."
Could Kirill Kondrashin have conduct a concert in Moscow on Tuesday, December 5 1978? Obviously not. Melodiya maintains its information. Asked about Kondrashin's schedule in Amsterdam, the Concertgebouw reveals that he was in Amsterdam for a concert tour that began on November 22. This implies he was there a few days before for some rehearsing sessions. Maybe Kondrashin was off Moscow since November 15, maybe even a few days before (if he had some tour in other cities). A wonderful CD issued by Globe (GLO 6 006) features a contemporary work by Boris Chaïkovsky, a pupil of Shostakovich, Theme and 8 Variations for Orchestra, that had been previously premiered in Dresden, on January 25 1974. Incidentaly, you have to know that meanwhile the world premiered has been released by the label Profil: try it, this is just a magnificent performance. The Globe CD features Moscow previously unpublished performances, among which this Theme and 8 Variations, performed on November 5 1978. As a matter of fact, this is the last trace of a Moscow concert conducted by Kirill Kondrashin.
Thus this new version of Myaskovsky's 6th Symphony provided by Melodiya also becomes extremely interesting for extra musical reasons. When was the recording shot? Maybe it was broadcasted in Russia on December 5 1978. But it can't have been performed there that very day. In fact, granted the severe reactions against Kondrashin after he defected to the West, we may expect that Russian people perfectly know when he left his country. There should be no hesitation about that fact.
In "Richter / Ecrits, conversations" (1998), Bruno Monsaingeon quotes a notice in the kind of diary Richter regularly wrote (pp. 372-373): "Television. Movie about Kyril Kondrashin. (A conductor who fled Soviet Union. I very often did music with him). The simple fact of programing a movie about Kondrashin is positive by itself for our country. Who could have imagined it might ever have been possible?
I learn Kyril ended his life conducting Mahler's 1st Symphony. The movie is not bad, but some elements are tendentiously presented (shots filmed in a Police station, as well as the phonecab where he would have called to tell he would stay in Holland) and lessen its quality. (year 1990)"
It is difficult to imagine that Russian people don't know exactly when Kirill Kondrashin defected to the West. This is one mystery.
When was the Melodiya version of Myaskovsky's 6th Symphony performed and recorded? This is another mystery.
Unfortunaly, there are many others about his life and career. If anybody has informations about it, he will be most welcome.