I have no idea which issue mine is. AFAIK it doesn't have the address and data bus brought out on the rear edge connector, but does have the holes for keyboard switches.
The clear buttons in the original key frame are part of the 'metal dome' upgrade offered by Science of Cambridge. A machine without them has the rubber sheet which was totally unusable. I remember buying that upgrade, it was not much better.
The revised monitor was almost essential, but as ever there was a minor problem with it. IIRC it used the Sense A input for something (single-step related
) and if you didn't realise what the cryptic comment in the instructions meant you ended up with a machine that wouldn't run user programs. I fitted the new monitor ROMs, found nothing would run and actually put the old monitor back for a time until I realised what was going on. IIRC tying Sense A either high or low (I forget which) cured things.