I believe this is a Deluxe Colson model. It has the same recessed rear step plate design as the Colson Imperial model. The Imperial trikes were top-of-the-line with more chrome parts as the one in my thumbnail photo. The Deluxe series were the next step down in features and price. The paint scheme and colors match the catalog page in the 1950 catalog but that same scheme and colors could also have been on models a little bit on either side of 1950. In addition to MLC mentioned by Rambler, the CABE and Ebay are also possible sources for replacement tires. You have to heat the tires up in scalding hot to boiling water to make them pliable enough to stretch over the rim. I tried one cold and can tell you it doesn't work and the tire will most likely split wide open. Oh, and I just saw you sent a PM about this trike, so I hope I've answered your questions. Just curious...is yours a 12" front wheel or 16"?
I think your Colson will clean up very nicely and worth the effort to spiff it up. Colson's are very well made tricycles.
Dave