Guy I've been working for lately has a few old Wadkin, Startrite stuff & the like for wood bothering. He has the space so he's hoarded stuff - several of which I don't think he's ever used.Most electricians have no clue how a motor or the associated control gear actually operates so i'm not surprised.
2 or 3 items he did want to use / has used and all they had on them was a 32A 3 phase plug - so plug them in and off they went

I found he had a proper NVR switch (2 actually) on the shelf in the workshop that no-one knew how to connect/test.
It took me a while to puzzle out how one needed to be wired in order to work, but I got there. I mounted it on a board with tails & a 3ph plug IN & a 3ph socket OUT (so that any machine he decided to muck about with could have a proper start/stop NVR mounted & connected).