Carb Advice

That's a fairly new looking carburetor to have worn throttle shaft holes, but that sure sounds like what it is. A lot of times that's caused by too much throttle return spring(s), but it appears you have one that's not a monster, so that might not be it.
Age wise its close to 20+ years old. Back in 20146 I used Sunoco 94 mixed with Cam II and stored it w/o starting it for about 4 months. That was the first time I had the carb rebuilt by a corner garage guy who claimed he knew how to rebuild them. I knew ethenol damaged the rubber but he only used a partial rebuild kit. I thought it would be completely disassembled, soaked, cleaned and all components of the Holley rebuild kit were to be used. Never really worked correctly after that rebuild. Woodruff Carb is roughly 100 miles SE of me, I'll give them a call and FedEx over to them. Rather rebuld it correctly tahn taking a chance on a new chrome plated one. Thanks.