I wonder whether remap would help you? as they help disabled people rather than dodderers (sorry!) you might have to be the one to say you need it rather than your wife, as I think your leg number problem might sway it
https://www.remap.org.uk/can-we-help-you/
they are a charity that makes custom equipment for disabled people. They are made up of mainly retired engineers who love a problem to think about and overcome! I have used them 3 times. The first time they made a custom bit of equipment for me, the second time they recommended something I could buy off the shelf that would overcome the problem and the third time they adapted something I had already