Quote Originally Posted by Gerald C Koch View Post
Swapping elements between lenses from different models is not a good idea. Even though the lenses may have the same name and specifications there may be differences in the formula. Once you determined that the rear elements were different you should have quit. Disassembling lenses is best left to a professional.
And, even if the glass is "identical", there's no guarantee the spacing of the cells in the shutter is the same. Once again, the taking lens must match the viewing lens.... the two lenses were originally selected to match each other within tolerance. The fact that you've trashed one lens already due to improper cleaning should tell you something. Good luck...you'll need some.