Mounted up the Merc.....
Don't panic! That piece of plywood will be replaced with a nice piece of Mahogany. Note also that the lower bolts will be replaced with longer ones and mounting the nuts with self locking nuts
The PTT is much longer in length than the original swivel mount,and so extends over that lower transom board that is proud of the rest of the transom, so had to make a spacer board. I decided to use stainless spacers to set the 3/4 spacer board back the remaining 1/8 inch so as to get the spacer board off the transom.
The Cavitation plate isn't as close to aligning to the bottom of the boat as I had hoped. Iit appears to be about a 1/2 inch above, but thinking it should be fine (?). Interestingly, the top to mounting bolts lined up perfectly with some previous drill outs, that had been plugged with dowels. I was able to just bang one dowel out, the other I had to drill.
To get the bolt holes in just the exact right location and to ensure the motor would be centered and hooked over the top of the transom (as in sitting on it) I made a pattern off the PTT. Worked just right.
Currently re-wiring the boat to include the PTT switches and an NOS vintage tach.... For the PTT up/down I am using individual push buttons for a unique look.
Hoping to get a shakedown run in soon....