If you want to approach those supposed owners on the Klov lists and you have good people skills I don't know why you shouldn't. Definitely don't expect the DU to be your future source for Marble Man (or anything). The owner of the game we know about (Scott at atarigames.com) is incredibly strong-willed and you have no chance of changing his mind so don't bother trying with him but the 2 randos, I say go for it if you actually believe them etc.
I wouldn't worry about making the collector to mame relationship worse. Life is short.