Thanks guys, I understand the general preference to keep things original, but before I make that decision it would be good to know if:
(a) what does it cost to get an original Midland booster rebuilt?
(b) the 9" boosters on Ebay for $100 that claim to fit '67-'68 Mustangs really do fit or is there a 'gotcha'?
(c) if the new 9" ones do work, are there any benefits to using a modern one? (e.g. work better with low vacuum engines)