Ok so 33120A arrived. Works perfectly - display bright and working fine.
Really dirty, covered in stickers and the fan is knackered though so I will strip it down, clean it and replace that. Fan is a standard Delta one which is typically obsolete but Sunon do one with same dimensions and airflow which is only 12dB (bugger all) so I will install one of them: https://uk.rs-online.com/web/p/axial-fans/8114144/
Me happy
Very good. Thanks for the fan info. Mine's getting noisy.
Ok have stripped it down (don't turn it on, take it apart!) and found no major crimes other than the encoder knob being bodged pretty badly and the fan being duff. No sign of any repairs on the output side of things which is a common failure. Keysight still stock the knobs so I will buy a couple of them I think for stock.
It has the panel cutouts for the TCXO option and the board connector (SMB by the looks).
Yep, those are the requisite cutouts for the Option 001 board's BNCs. You did good, bd.
Edit: damn I love HP / Agilent / Keysight. Phoned them up, answered by human straight away, took order for parts over phone.
+1: I've also had good experiences with Keysight, except for the time I asked for something for which they didn't yet have a process to fulfill. That was a bit of an ordeal, but it was sorted eventually.
I bought two knobs (incase I munt the replacement in the future) and they were £2.28 each
Yeah, knobs are one of the few spare parts that for some reason don't carry the usual hefty "spare-parts tax."