I know its a Kingston, only because it says so, but what model. Also is it worth it to rebuild it or should a by a Holly. It's for my speedster, so any suggestions??
Get a Simmons or Holley straight through for your speedster.
It is a 1915 - only Kingston. Prety hard to find a good one. They look great all polished up. As Kenny said there are better running carbs out there.
The bigest issue is the cork float. They can fall apart, or sink, either way the gas tank gets emptied on the ground if you are not around to shut off the gas.
I have a brass Kingston Model L with a tag on it, but it is an updraft carb. It is pre 1919, as the choke only has one attach point for a choke rod. It might not be for a Model T though, as it has to be pulled straight up to actuate the choke feature.
Martin, here is the photo and commentary from Bruce McCalley's black covered book.
That internal air flapper is lead or pot metal and usually in bad enough shape, so the carb will not operate. Reproduction flappers are not being made to my knowledge.
Keep that one as a pretty collectable (or trade it)and pick up a common NH or the staright bore NH and your speedster will thank you.