Replacement pocket door roller for Kennatrack Mfga Slider

I am looking to repair or replace this Pocket door Slide. The parts that Need are for a Kennatrack Mfga Slider with brass wheels with rubber treads. The wheels need to be replaced and the device that adjust the height of the door no longer works the round nut that slips into the door is either stripped or the screw is corroded and does not allow it to adjust.
Measurements are With out wheels 3" long by aprox 3/4" wide without or with wheels.
Thank you chip

Thank you
I measured the wheels and the one with worn "tread" was little more than 7/8 and the brass wheel without tred is 11/16. The one with tread i think could of been 1 inch with a none worn wheel. I also notice that the inside of the wheels were different but axel sizes were all the same size. you can see the difference in the pictures thank you chip

I have a roller very similar to this and need two of them (bent one trying to get it out of the track!).

My roller is 3 3/4 inches long by 7/8 wide (with wheels) and the wheel diameter is 11/16, made of nylon. The wheels just slide on and off of the axle. There are no markings on it to show who manufactured it but the house was built in the 1950's and the track assembly is original to the house.

Thanks
Steve