Pulled the roller out to find the plastic ring gear is almost like new. The steel pinion is also in good condition. The roller has 79 teeth and the pinion 12. Roller outside diam is 7 5/8 in, inside to gear points 6 3/8in pinion 1 3/8in. Sorry vernier only have imperial measure (I need new set) [Linked Image]

If it don't go its not good.