The pictures PotterJ are of my Potter & Johnston 15" shaper.
The conversion from belt drive to the 4 speed geared Lima motor are shown here.  It looks like a pretty clean job, possibly a factory installation.
   The next set of pics is of the power down feed mechanism for the clapper.  Mine is missing some of the pieces, which I am hoping to remanufacture.  I believe that I now have an understanding of how it works - mostly.  The function of the indicator or stop that lives in the half moon shapped hole in front of the ratchet feed is still a bit of a mystery however.
Brad