René Lassartesse (or Jack de Lassartesse in France) is a big heavyweight wrestler from Switzerland. He wrestles everywhere in Europe and was a Main Eventer. In France, he was build as an arrogant American (blonde hair, chewing gums).
We have two matches in his prime :
vs. Michel Allary available on Youtube
w. Robert Duranton vs. Andre Drapp & Bernard Vignal (a great tag match that I have on my hard drive)
Later in his life, he has a great match against Franz Van Buyten from 1987 ! As you can see, he had a pretty long career. He would became a promoter in Germany (William Regal talks about him in his book).
I'm sure OJ knows more so he is the guy to ask infos.