doug,
Multico have not been manufactured for 50+ years so you have little chance to find new parts.
What you could consider is to make the parts yourself. eg
1) Use M14 upto M20 rod with a screw thread. You will need to bore out the existing mounting and retap with appropriate thread
2) Its easy(ish) to make a wooden handle to fit the outboard end and use a pin or grub screw to fix it as well as epoxy
3) The pad at the working end would be made in a similar fashion ( maybe oak) but the difficulty would be if you wanted it to swivel. In which case you need to round over the screw thread end, drill a hole for a pin and find a socket to fit the end of the screw thread...I know not where but start with Arcoy.
good luck