Futaba S3305 servo, metal gears, high torque, analog, vintage. Not a particularly fast servo, but metal gears and high torque would be great in your kids basher for the price. Works as it should.

124 oz-in torque

0.20 @ 60 degrees

YouTube video showing it working:

https://youtu.be/Vkt3iiMZPCc?si=lNrddrZslaz15FND