This is what I could find on AGD's website:
http://www.btinternet.com/~bellagio/gigs69.htmlMay
5th European tour
[all shows w/Paul Revere & The Raiders and Joe Hicks unless noted;
two shows each night unless noted]
30 - Dome, Brighton, England
31 - Hammersmith Odeon, London
June 1 - De Doelen, Rotterdam, Netherlands
1 - Concertgebouw, Amsterdam
2 - Radio Bremen TV Studio, Bremen, West Germany
3 - Amerikaans Theatre, Brussels
6 - Odeon, Birmingham, England
7 - Empire Theatre, Liverpool
8 - King Edward's Nurses Home, Leeds [one show, no support] [3]
8 - Free Trade Hall, Manchester
9 - Odeon, Glasgow, Scotland
13 - Jahrhunderthalle-Hööchst, Frankfurt, West Germany* [no support]
14 - Deutschlandhalle, Berlin, East Germany [no support]
15 - Munich, West Germany [cancelled]
16 - Break Away/Celebrate The News single released
16 - Midi Premiere TV Show, Paris, France*
16 - Olympia, Paris, France [no support]
17 - Lucerna Hall, Prague, Czechoslovakia [no support]
18 - Hala Rondo, Brno [no support]
18 - Song Festival, Bratislava [no support]
19 - Ostrava*
20 - Keimolan Juhannus Juhla, Vantaa, Finland*
[w/The Spede and Simo Show, plus car stunts (!)]
21 - Pop festival, Antwerp, Belgium
22 - Finsbury Park Astoria, London, England [w/The Rainbow People and Marmalade]
?? - NRCV TV Studio, Amsterdam, Netherlands [possibly 21st or 22nd]
No trace of anything Russia here...
There's a 2-week gap after that 22nd of June (on July 8th they perform on the Mike Douglas TV show). But one would think that after 4 gigs in Czechoslovakia and 1 in Finland a trip to Russia would be more logic directly after that then first travelling to Belgium/Holland/England.
I'd be very interested in seeing that Czech article you talk about (if I understand it at all...)