Hello
In the belief that I was confronted with a nice large journal crankshaft for my A 10 I bought the item hopefully depicted here. It was advertised as BSA 650, and I was happy to see the absence of provision for an alternator, so had to be for A 10. The journal was measured by seller as 42 mm (and since no A 7's were large journal, to the best of my knowledge, again had to be for A 10). Hooray, large journal! However, I can by crude means only measure the stroke to about 70 mm, and not the desired 84 mm. The casting bears the number 68-175-4001.
Can anyone help me to identify this crank, many thanks in advance?