I have been working on my model 15 and found something tonight that I hope explains all of my issues that I have been having. I have a holding magnet on my machine, and I found i have a cam on the main shaft for a pulling magnet. My cam is stamped with a 'CX' and it should be stamped with an 'M'. I have a parts order into Paul, but am hoping I just need the new cam, along with the correct retaining disk on the end. 

Would this cam mixup allow for 'almost' perfect copy with very little range on the rangefinder?

Am I going to find that I need other supporting parts when I change out the cam?

Hoping this fixes my issues, I am practising my stress reduction meditation working on this machine. I feel it is so close to working perfectly, but I keep failing to get there....