Nascom 2 keyboard connector

Close, but no cigar :-) The 5-10 (5 valves 10 watts) used an EF86, ECC83, 2 off EL84 and an EZ81. All are on B9A bases, so I'd only have needed the 3/4" punch. I can't remember the hole size for the Bulgin plugs used for the mains and speaker connections, but I think it was smaller than 1+1/8". Now, had you said the 5-20 (line up : EF86, ECC83, 2 off EL34, GZ32), then I would have needed the 3/4" and 1+1/8". And had I also been building the companion FM tuner, I would have needed the 5/8" (for the EB91 detector double diode, I think the B8A 'rimlock' sockets for the EF41s would go in a 3/4" hole). Yes, I do have the appropriate Mullard books. And the Williamson reprints. And the GEC book on audio amplifiers (which starts with the Williamson and goes on to a monster with a rated 1.1kW audio output power). -tony