For what it is worth, I stumbled upon a relatively comprehensive account of the history & development of Aikido here in Hungary.[Thankfully its in English...]
Despite its humble beginnings in the 60s it appears it didnt really get a jump start until 1984. Tamuras first visit wasnt even until 1988 - thereafter he visited practically every year it seems.
In fact, I believe he will be in Budapest this Dec. 13th for Dan rank testing.
[Maybe I will get the family and head down to Budapest to check it out and get some photos... should be cool.]
Anyway, for those who may be interested:
Who knows, maybe one day the 5 organizations will come together and form something under the Hombu in Japan.
From what I can tell 4 out of 5 are cooperating together... so maybe its just a matter of time.