My friend owned a pair of these many years ago. I liked them a lot. I would get them..or at least
listen to them. In regards to surrounds...yes is a difference. It has to do with the compliance, roll size,
angle or straight edge etc. Here is one example: I own a pair of NEW LARGE ADVENTS. The original
surround was very "loose" and springy. Someone refoamed with generic surrounds (much stiffer) before I bought them. This raised the original Fs one one of the drivers from the original value (approx 25 HZ) to over 40 HZ. Hmmm...so you would think that ruined them huh. Actually...nope. Cant hear a difference at all. Not sweeping test tones, not with music, nothing. They play perfectly. So, in "theory" they changed but with a constant changing, dynamic music input there is no difference at all. Dont get too hung up on the surrounds until you listen to them. I bet money you will like them. And unless the original equipment mfg offers surrounds as a replacement part most vintage speakers from the 80s will have "generic" surrounds. But let it bug you unless you hear obvious abnomalities while they are playing.
Augie