They look like the common Motor Wheels which were used for quite a few years. They are the Firestone RH5°. You will probably have a difficult time trying to find anyone to change them if you have a flat. I would start looking around for the Goodyear type wheels. 55 and newer will fit and they are a lot easier to find than the earlier 4.75 bore. 22.5 tubeless were actually standard for the late 50's, but very few of them were ordered. There are some around, but they are hard to find. They haven't been produced for some time.
