Well one thing led to another and he offered me a mint B77 high speed
unit for what I considered a very fair price considering he was shipping
it from Switzerland to the USA!
A capstan adapter can be used to change the speed on a deck. A number of pro audio decks use this to do 30 inches but it can also be used to go from 7.5" to 15". If you've ever wondered why many machines (such as Ampex) have a threaded hole in the top of the capstan, its there for a capstan adapter. You might run into an issue with equalization but NAB 7.5" and 15" EQ is the same.