That's a great way to mount your benchtop tools Graham. I need to do something similar in my shop too, Cheers

Nice system for some of your tools. I've seen an alternative setup here in the US being used by some tradesmen in their work trucks: the tool is mounted via plates to a receiver hitch plug instead of a ball for pulling a trailer. I've seen anvils, grinders, drill press, portaband saw, bender, vise, etc and they're not restricted to receivers on trucks. Receivers can also be mounted to workbenches. If they have a support post under it, you can use devices that you can beat on without damaging your bench. Put a few receivers at each end and along the length of your bench, you leave your top surface clear and clean, and you can reconfigure it for whatever job you're working on.