I want to recommend a highly reputable mechanical rebuilder I found on eBay for Rochester B's (only stuff he works on). His username is betsyb10. I have had two rebuilt by him (one as a spare) and the installed one works perfectly. These rebuilds were $50+ shipping, he does only one at a time and they are all tested and tuned on a running STOVEBOLT 6. This guy is top notch if you are lucky enough to land one of his auctions.