As for the accelerator pumps…….my experience with Holley carbs that have been sitting…..when the pump levers act like the pump is “solid”, is that’s not usually the symptom of the diaphragms getting/being stiff.
When they’re “solid”, it’s because they are hydro-locked.
They check needles will be stuck to the seats, and more often than not they won’t break free from pushing on the pump lever.
When I’ve run into that, sometimes some light tapping on the squirter screw will free them up, but that doesn’t work very often.
Just remove the squirter, and with something like a sharp pick, try and wiggle the top of the check needle.
Once it moves, you’re all set.
Reinstall the squirter and test it……you should be good to go.
If they’ve been sitting for a fairly long period of time, it’s a good idea to pull the needle out and make sure the tip isn’t corroded.