i recently purchased a Rolex 1560 on ebay, the watch was disassembled, the balance bridge was well worn in comparison to the other watch plates showing brass under base. the person said it needed a minor hairspring adjustment, I assembled it and adjusted the hairspring several times to get it correct but it was TOO far gone,i think someone didn't realize it had a hairspring protector in it and pulled the balance with the bar in the way thus stringing out the hairspring, long story short I purchased a new balance complete for $250.00 on ebay that had been opened but not installed, I also opened the mainspring and it was metal mush, worn so badly I replaced it with a 1570 mainspring and a used barrel I had that didn't look too bad, cleaned it ,reassembled it ,demagnetized it. and it is gaining about 10mins /hour, (1) could it be the generic mainspring not freely moving in the worn barrel? ANY SUGGESTION?? thanks rob