There are many ways of "restoring" alloy parts on an Airhead. If you want the absolute Rolls Royce of alloy refurbishment there is only one guy in Queensland to go to.
He knows BMW's and all about the oil galleries, and other trickey bits. His work is orders of magnitude better than any I have seen elsewhere. He is a one man band (like me) and he takes great pride in everything he does.
Any one working in the automotive trade these days who tries to tell you that they do everything them selves is stretching the truth. Reality is that whether you are fixing a bicycle or a drag line..you are going to need specialist machinists, welders, fabricators, ...for our bikes ....hard chromers, frame straighteners, painters, upholsterers, parts suppliers, auto electrical suppliers and specialists, bearing suppliers and so on and on.
I only use people like Wayne for any work I do that I can't do myself. As I've said repeatedly (an learned the hard way over the years) These top end specialists are not always the cheapest but they are always the least expensive in the long run.