soda blast....sure if you can find someone to do it for you.
i have beadblasted a lot of cases before. all you need to do is clean it in a clean parts washer afterwards. that's why i normally had 2 parts washers. one was for heavy cleaning, and one was for detail, or final assembly work.
Nothing special that you wouldn't already have for removing the top end. Splitting the cases really involves no more than removing about 10 more bolts than you would have already removed to get the cylinders and oil pump off. You'll have to (should) install new oil seals but that doesn't require anything more special than a large socket to put them in place.
And unlike Tex's advice. You don't need fancy parts washers either. As long as you have a dishwasher.
Well I'm really leaning towards splitting the cases, but I am working on other things. Got some carbs on the way, got the clutch cover and top engine mount I needed (how did people do this before ebay??) started stripping the frame for paint, and am moving on to all the little stuff. Here are some update pics.
I have just found the inspiration for my re-construction. Does anyone know what that seat is, or do you think is was hand made? I will probably go with smaller blinkers, but I think this is pretty sweet.