Landlord - EICR 'unsatisfactory'

Completely agree with Buzz.
The report is not written badly and the price is fair. You need to get the work done in order to make it safe for your lodgers.
I'm sure if you get enough second opinions you will find one that says the work is not required, you are then tempted to follow this advice rather than all the others advising you to get the work done.
It genuinely is a fair price.

Thank you for the further replies and considered advice. Got in there today and took a few pics. I can't see any CPCs at the two switches I looked at. Don't think it is conduit system (nothing evident). The bathroom light used to have a screw-on white glass bowl - no idea where that has gone (the base of that fitting is plastic). I didn't try tripping the RCD (the tenant was at home and I didn't want to disturb them unnecessarily).

Consumer unit is Tenby with Legrand MCBs.

Cct 1 is cooker point (with integral SO).
Cct 2 is shower.
Cct 3 is sockets in kitchen.
Cct 4 is 3 twin SOs in lounge, 1 single SO in lounge, 2 twin SOs in bed1.
Cct 5 is immersion heater.
Cct 6 is 1 single SO in bed2, 2 single SOs in lounge.
Cct 7 is lights (7 fittings - hall, kitchen, bathroom, bed1, bed2, 2 in lounge)
Cct 8 is 2 twin SOs in bed2, 1 twin SO in hall, fused spur for alarm.

I think I see some 7/029 in ccts 4 and 6 (sockets) and 3/029 in cct 7 (lights). The flat is all-electric and there had been storage heaters at some point in the past (I now have plug-in oil-filled rads). I think wiring to one or more of the storage heaters was reused to fit SOs instead. It is a first floor flat with concrete floors. There is another flat above so I think the ceiling will be concrete as well.

One more pic - front of MCBs.

From the pictures, it looks like the consumer unit was a newer replacement to older wiring.

Some new Legrand parts are still available - though can only find up to a 63A RCD immediately available, which might not be a suitable replacement depending on circumstances.

The pictures of light switch wiring/back boxes does look like unearthed cable though, so a rewire of that circuit is going to be needed at some point, even if it was possible to theoretically comply in the short term with legal requirements by ensuring every fitting/switch is a type that doesn't require earth. (Assuming the RCD issue is fixed regardless)

The bathroom light fitting will be an easy fix with a straight swap replacement LED surface fitting, so should be no big issues there.

You may be able to find a cheaper price with some shopping around (smaller firm that isn't vat registered), but you may have to factor in a new EICR on top, or be sure that you have suitable written confirmation that the C2s on your report are either resolved, or not actually issues.

If a replacement CU is being quoted for, then I would suggest type A RCBOs with SPD, and you will probably be covered for many years to come with no more surprises at future EICRs.

RS Components appear to stock Legrand RCDs and include an 80A one in their range. A replacement CU with Type A RCBOs for each circuit would be better long term solution.