If you want the booster restored professionally:
"Booster" Dewey does a great job, he's rebuilt other car boosters for me in the past. He advertises in Hemmings all the time. He generally gets about $100 and does a fantastic job. His number is (503) 238-8882
According to "Booster Dewey" (found in Hemmings) sometimes, gas fumes leak from the intake manifold into the booster. There should be a check valve at the hose junction on the booster. The gasoline fumes will eventually ruin the rubber bladder in the booster. I've been thru this a few times with different cars that I have owned. You can buy a generic check valve at your local Auto parts store, and I would reccommend this if you're installing a freshly rebuilt booster.