I need some advise on a parts book mystery. I removed the cam gear from my '60 A10 Spitfire and my '53 Super Flash. The gears were stamped 67-338. I also had another 5 67-338 on the shelf. The 49-53 as well as the 1960 parts book shows 67-337. My 1970 A65 parts book shows 67-338. My price sheets from 1950 to 1965 show no supersession or consolidation of the two. In checking on the web with a supplier, both photos appear indentical, down to the timing mark location.
I have no A65 parts in my shop, only A10. Where did all of these 67-338 come from?