Before condemning the carb, I would test the vacuum advance on your distributor to see if applying vacuum truly is moving the dizzy breaker plate. This can be done using a mity-vac, but don't pump the trigger. you only need a little bit of vacuum. If the breaker plate moves, hold what ya got and see if the breaker plate holds it's position. If it does not, and moves back to home plate, your vacuum canister rubber diaphragm is busted and needs to be replaced. This would cause hesitation upon acceleration. However so would other things.
BTW, the Holley 1904 carb is probably the EASIEST carb in the world to rebuild and I encourage doing it yourself if you want to save money. Get a quality kit from Daytona Parts or Mikes carburetor parts.
First thing to do is check for any looseness in the butterfly shaft in the base of the carb. If it is sloppy, ask Sal Cicala (on this forum) if he can bore out and install bushing for you and have him finish the rebuild.
If shaft is okay, I would tackle the job myself. You'd be surprised how quickly you can learn to rebuild this thing effectively.