Not the answer to your question but a G**gle search found two firms in this area:
www.speedycables.comhttps://ryanlinleyrestoration.co.uk/morgan-lotus-vdo-speedometersLooking at the remaining numbers and Fairchild parts list, on the plus side, I think there is a good chance that you may have destroyed something which is a standard logic part rather than a custom device. So, if you can find the part number, it should be available.
Good luck.
