Complex sentence: During 80s, old trams T3 were still in production and the fleet restoration with T6B5 vehicles manufactured for Soviet Union in 80s, was not capable for systems in Czechoslovakia.
Split into simpler sentences: During 80s, old trams T3 were still in production. And fleet restoration with T6B5 vehicles manufactured for Soviet Union in 80s, was not capable for systems in Czechoslovakia.