They were Avia S-199's I believe (have to look it up), basically Czech built Bf-109-G14's with Jumo 213 engines. Correct me if I'm wrong... it's all from memory.
Didn't really have a good reputation, I believe it was called Mezek, meaning mule, by the Czechs.
But... how would these match up against a late Spit? Not very well I guess.