i have seen another crank like this at the kempton bike jumble in the UK, it is an A10 but it has been modified, the timing side has been ground down and a sleve fitted for the needle roller conversion, so without the crankcases it is useless , it can't be easily put back to standard. from what i could see of the one at Kempton it looks like a mod for racing as the flywheel had been modified and loads of holes for balancing which might mean it had lighter con rods and pistons ( maybe a short rod A10) so without the rest of it, it has to be a no go.