Not sure if Ryan@BlueCat has the equipment for a crank seal test - but he might. Tom Manley (Manley Cycle) also might, but I'm sure that Hitching Post, Towsley, etc will have it.
Ryan told me recently that BlueCat is going for the bigtime - full service shop with paint & body work, performace tuning etc. I might have the opportunity to do some work with him - which is something I really miss doing. Can't do hard/heavy stuff anymore, but I'd be fine doing electrical work, carbs, engines or other bench work.
You can probably test the magneto-side seal yourself. If you can get the bike running with the magneto cover off, try to get a shot of carb cleaner in behind the stator plate, in the area where the crankshaft comes thorugh - that is the seal area.
If a spray of carb cleaner onto this area has any effect on engine RPM (other than the cleaner fouling the points..) that seal is sucking in air. There may also be evidence of gas/oil mix around the bottom of the mag/stator plate. Either of these are a dead giveaway. You may even be able to hear it.. put a piece of tubing almost into your ear, and place it near the edge of the stator plate. Listen for the Sounds of Sucklence.