In 1995 there is a photo of the decks labelled VT0 and VT3, VT1 was the Umatic that no one used and VT2 was the VHS or what later became the SVHS. So when did the ident system change?
I joined in October 1996, and they were certainly letters by then. The only flirt with numbers I recall was when I bought a pile of identical VHS recorders for tape copying, TS1/TS2/TS3 ('the stack' or 'tape suite' as you prefer) Sprow 07:57, 31 May 2007 (BST)
Here is a picture from May 1995 (I am so in trouble now). It is the only clear shot of the labels I can find. Someone must have changed them between those dates. --Owain 21:04, 31 May 2007 (BST)
In the original scan of 
you can read the names of the machines (on yellow LX tape), as they were at EN 1993. I'll try and post them on Monday if I get a chance. Richardash1981 22:40, 2 June 2007 (BST)