Hi B,
getting lots of good responses 
with swapping out parts, under decent magnification the eye is quite good at picking out suprisingly small differences. If it looks good, has the same amount of teeth, pinion and wheel heights match, overall length of the arbor with pivots is the same, pivot lengths the same, then the next thing is to try it. You can always check measurements if you run into problems or want to check a certain aspect of what you are swapping. Take your time, be careful and all will be good
Paul.
