Long story short, I was rebuilding our Zenith carbs for use on our 914-6. They are not correct, but what we found on the engine. In the process, I discovered they have a couple bent throttle plates and shafts. So I suspect that means the throttle shaft bushings are damaged and I would probably be in over my head for refurbing them with a good result. Sold them off to a carb restoration business. Hopefully they can be refurbished and useful to someone else’s restoration.
I guess the excuse (er. hunt) to buy correct Weber IDTP carburetors is on.