After blasting all the rust off both speedo and clock backing plates (and finishing up all the rough edges on my cuts) I sprayed them both in aluminum Rustoleum. I set the cardboard insert back in place
and set it aside. I took the original clock
took apart the guts and with my diegrinder, cut everything off flush. Now all that remained was the flat piece and the stands that the face screws onto. I drilled a bigger hole into the center of the plate and slid in on the clock, which was then tightened down.
I screwed the faceplate onto the clock with the little factory screws
put the clock arms on on set it back in the base!
I already found and ordered 2 pieces of convex glass on Ebay for $20 for the pair. I need to go to Radio Shack and find an AA battery holder with some wires and solder those to the clock, to make it easier to change out. Need 2 5" square edge O-rings to put between the tapered piece on the glass that rests on the gauge face itself. When finished, I'll have about $25 and a few hours time for a perfectly running clock. I rebuilt the speedo guts myself and everything purrs smoothly and a total of about $15 into it. I'll put pics up shortly once they are back together completely.