I'm resurrecting this thread for two reasons. I just bought two of these on eBay, one was $4 and the other was $9. I plan on cleaning them up and using them for more 6x6 fun.
1 - It looks like the earlier models had a nice metal advance knob, instead of the later boring plastic one. Are the advance knobs hard to switch out?
2 - If you end up with a model that doesn't particular care for 120 reels, are the reel modifications difficult? From what I've researched its looks like its just a little filing and clipping. I prefer to modify 120 reels as I'm not to sure that I'd be able to re-spool it properly.