Date   : Tue, 22 Jan 2013 20:34:19 +0000
From   : public@... (Daniel Beardsmore)
Subject: BBC Micro keyswitches

OK, SMK is confirmed off-list -- SMK branding found on the switch base. From
that I think it's fair to say that Types 1, 2 and 4 are definitely Futaba,
SMK and SMK respectively.

I don't know about Type 3 -- one would imagine it's PED, but I've never heard
of them, so I have no basis for recognition, whereas I recognise Futaba and SMK.