Chek out this Ebay listing:
Even I can tell that theese crank knobs are not gray GB1 style. 
But I found them a little different than the the knob pictured here at GBfans.
Is this the “correct” knobs? If so price seems reasonable.
That’s the larger style knob so no, not correct. Also it’s against forum rules to post links to live ebay auctions
Oh, sorry about posting the link. I cannot edit it since it’s the first post of the thread. So a moderator may delete this thread.