RS Cosworth Analogue Replacement Motor

[RayWood]

I have an circa 1995 analogue Scalextric set with 2 RS Cosworth cars. One of the cars works fine but the other stops moving after a couple of inches although I can hear the motor running. After removing the body shell I can see that the prop shaft on the motor jams after a couple of rotations, even if I try to turn it by hand. I am guessing that the motor needs replacing but not sure what type I need to get so looking for advice and recommendations on where to get it from. I don't have a lot of modelling experience so looking for option with preferably no or minimal soldering. Thanks in advance.
(P.S. I tried to load an image but website timed out)