I *think* he is Eugene Petrov.
That looks like Igor Panchenko, a local SoCal modeler. His contact information is in the PAMPA directory.
By the way, in case anyone would like to see the magazine article the Russian stunt model by Sirotkin, here's the link:http://publ.lib.ru/ARCHIVES/M/%27%27Modelist-konstruktor%27%27/_%27%27Modelist-konstruktor%27%27_1969_.htmlThe article is in the August '69 issue.