As Ken points out, one of the flipper assemblies for this woodrail are no longer available, unless you get it from a salvage machine. That is the two-piece shoe and shaft assembly. All modern flippers have a one-piece shoe and shaft.
The good news is that you can easily install the newer style shoe and shaft, and any other newer flipper parts for this machine, as I had to do with a Skill-Pool I rebuilt a couple of years ago (see pic). I agree that The Pinball Resource is an excellent place to get vintage Gottlieb parts.
One other suggestion I would make for this game is to use LED bulbs for the rack of pool balls on the playfield. Personally, I don't like to put LEDs in vintage games because I don't like the way they look, but this situation is one of the rare exceptions. The original incandescent lamps get so hot when a lot of pool balls are lit that they tend to melt the plastic pool ball covers. So, using LED lamps here will help to preserve the game cosmetics.