J,
I tried them but it's just too tiny even for them.
It's the little bolt/screw in front.
I tried the 3mm copper pipe but it's just too flimsy/dicey for me. The OD is 3mm and I drilled a 2mm ID and then I chickened out.
I'll visit the hobby shop in Som West and/or try one of the machining shops in the Strand on Monday.
Everything else is in such good condition and now that I've found replacement DC motors from Mantech I just have to get 2 bolts made up. I suppose it's a matter of finding the right machinist

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A hobby machinist would be 1st prize

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Thks for your offer but I think at 2.5mm dia one needs extreme accuracy and a very delicate touch.
Any other advice?
George