I know this subject has been beat like a rented mule. But here we go. I found a dot tire that looks very similar to 30’s or 40’s Indian motorcycle tires. Have a nice tread pattern in my opinion and would add a beefy look to a simplex. I don’t know how tight the tolerance is for tire size on a factory simplex rim so here I am sharing the tire specs compared to a simplex tire from Coker and they appear very very similar in sizing. Does anyone see a reason why this would or would not work?

A complete unrestored but kind of crusty anniversary bike just came for sale near me if anyone is interested. It is listed for $3200 I’ll try to get pictures posted

Here a couple pics of the bike Pete

I’ll take a picture of the zenith carb. I can’t find another one that matches it. But it is very very very similar to the carb you posted which is why I thought it might have been something they switched to in the later 50’s