I've got a sheet metal nibbling-tool that I can use to cut rectangular shaped holes in sheet aluminium pretty easily, it cuts nice 90 degree corners, so, if my friend can't find the original power cable, I'll seriously look at retro-fitting both the desk and the power supply with new, and easily source-able connectors, as much as possible, I really want to try and get the desk restored so it's in a good, and usable condition, the prices for spare parts look reasonable enough to make restoring the desk a viable proposition, it may take a lot of my time though, but it'll be worth it.
Just so happens, I enjoy a bit of a challenge anyway.