UncleRichie,
I'm a resident of St. Louis, where I believe your pumper was built (Central was located here, on Forest Park Boulevard, I think). They're terrific trucks, and there are quite a few of them around.
I've got a '41 truck, and I think my seals came from Jim Carters Chevy. I use them AND Chevs of the 40s a lot.
I've also had really good luck taking the old seals (and bearings) to a local bearing house, where they can match them up pretty easily. It's a little pricey sometimes, but can save a lot of aggravation searching (and getting the wrong ones!).
I agree with the previous posts - Welcome, and send photos soon!
-Michael