Brake boosters are relatively inexpensive. That looks like a single diaphragm 9 inch booster. A modern 2 chamber mc should bolt right up. The aftermarket produces a copy of the corvette mc. I would really look into getting new parts and make certain they all play well together. The brakes are jut too important for any monkey buisness.
I have had some recent experience with brake boosters in my 1959 gmc. I had an 8 inch single diaphragm booster, which was malfunctioning. I replaced it with a 7 inch dual diaphragm booster, and then again with an 8 inch dual diaphragm booster. If younhave the space, it is worth it to go for the dual diaphragm boosters. They work on lower vacuum signals and decrease the pedal effort significantly. I would reccomend going with a 10 or 11 single booster if you have the space, or a 9 inch dual if you don't.
