There is a very good method for setting crankshaft endfloat on the Cheshire Branch website
www.cheshirebsa.co.uk on their tech tips pages. You only need a set of feeler gauges, an L shaped bracket with a threaded hole and away you go. You only need to separate the cases once.
By the way, I'm not too keen on the idea of skimming the crankshaft axle to allow the bearing to fit a bit more easily. In my experience there are quite a few owners who don't tighten up the crank nut enough, consequently the nut comes loose and the bearing spins. If the bearing is still a tight fit it has a chance of staying put until routine maintenance in the primary chaincase brings the problem to light. If you use the correct bearing and a proper bearing puller I don't see a problem. Also, the bearing needs to be tight on assembly to grip the shims, otherwise there is the danger of the shims slipping down onto the axle radius preventing accurate endfloat measurement. I know people have mentioned Loctite etc. but if everything fits the way BSA intended you can spend your Loctite money on something more useful like petrol or beer (but not both!).
