Sorry, but I have never heard of a place where you can get new rubber tires put on used lawnmower wheels.
But as a builder who has messed with both, I say switch to non-bearing wheels. Regular LawnBoy wheels have grooves that you fill with felt washers that keep dirt, etc. from getting to the inside where it wears away the plastic and make the wheels rotate smoothly. These wheels are
cheaper and
lighter and last a very, very long time. I have had issues with NOS "original" bearing-wheels not being constructed properly (the axle not welded exactly even with the hub so it wobbles as it rotates), which was really irritating given their high cost. I have also machined grooves in aftermarket wheels to accept LawnBoy felt washers for the same reason LawnBoy wheels have them [
https://www.lawnmowerforum.com/threads/new-wheel-depth-and-felt-washer-well.60931/#post-370968].
If you are set on having bearing wheels, there after aftermarket ones that fit. Years ago I put an aftermarket set on my "daily driver", an S21ZPN. They are OK, not any better than non-bearing ones in IMO, but they cost more, they're heavier, and don't give any advantage at all (over regular LawnBoy wheels) as far as I can tell. When they go, I'll switch back to the original plastic ones.