i'M NO EXPERT ON THE COST. but.............
Several have had it done, with glorious results. I believe there are 2 prices: a lower one if you are the original owner with documents, etc, and another for a different owner.
A few yrs ago, The V.C.C.C. sent one for a rebuild. It was raffled off. The only issue I ever heard of was that some of the replaced parts are not original colors.
But, I've seen them. They look and operate perfectly.
Others in here will know far more about it.
But, they loved the results.