Here are a couple of photos. I opened one 25, cleaned it up, cut the case, etc. After opening the second one I saw some differences.

Left:
Piston skirt is cut out
The Crankpin is smaller - .375
Counter weight is larger
The Cylinder is not chrome looking, its rather dull
I may have damaged the chrome with chemicals?? This one I tried lots of different chemicals on for cleaning purposes.


Right:
Piston skirt not cut out
Crankpin larger - .395
Counter weight is smaller
Cylinder is nice shiny chrome

These both had the same model numbers on the plastic cases
I figure don't use the one with the dull cylinder......