Try these. RC4WD came out with these for some lego kit. They are 1.2" dismeter. The WPL wheel bead is around 33mm, which is 1.299". I have the Rock Crushers. They fit WPL wheels nicely.
https://store.rc4wd.com/12-Tires_c_964.html
These are wheels I designed a bit larger than the stock WPL bead...