I found one Russian site (not
www.allaces.ru ) that stated that they had Airacobras from May43-May45. The unit's commander Guards Podpolkovnik Aleksey Borisovich Panov (ace and HSU) was killed in an "Airacobra" 12Sep44 near Praga, Poland. I don't know if they were talking about the P-39 or P-63.