A smart seller would make one to suit a 62 1/2 tooth bull gear.
Maybe one of our experts could model a 1 MOD or 1 DP 60t external gear meshing with 20 teeth of a 62 1/2t internal gear (or 65t external / 62 1/2t internal) and put a number the lack of fit. That number would scale directly to the actual DP of the Myford gear.