The
Best Practice Guide for inspecting and testing did have an example of a label but this has been removed, so getting an EICR done it is possible lack of CPC would be coded what is important for rented accommodation is it does not get code 2.
This is from BS 7671:2008 but each one says some thin similar
BS 7671:2008 Requirements for Electrical Installations was issued on 1st January 2008 and is intended to come into effect on 1st July 2008. Installations designed after 30st June 2008 are to comply with BS 7671:2008.
The Regulations apply to the design. erection and verification of electrical installations, also additions and alterations to existing installations. Existing installations that have been installed in accordance with earlier editions of the Regulations may not comply with this edition in every respect. This does not necessarily mean that they are unsafe for continued use or require upgrading.
it will be noted it is design date not installation date, so a 4 year job could still be having items installed to the earlier edition so swapping light switches to another one stipulated on the design is still allowed.
However light switches are not often marked as class II neither are ceiling roses, so although they may had the little bungs that go over screw holes, or use nylon screws and be quite safe, without the
mark on the switch or ceiling rose how does an inspector watch his back and sign it off, so one can understand the difference between potential dangerous and not complying with current regulations. There was a code 4 for not complying with current regulations but it was removed.
So no CPC was allowed before 1966 but the first BS 7671 only came out in 1992 before that it was not a British standard, so BS 7671 has never allowed no CPC to lights.
Since in 1966 there were no RCBO's the installation is clearly not as designed in 1966, yes I know with RCBO's it is safer, but it is not as designed in 1966 so any inspector could say it is non compliant. As to potential dangerous well 230 volt AC is always potential dangerous it is rather a silly phrase, I would say no it is not potential dangerous, but that is a personal opinion as is everything on an EICR, which is why the person doing the report needs professional indemnity insurance, Best Practice guide is just a guide, if he is a scheme member, then the scheme require him to follow their instructions, even if he personally feels they are daft.
I personally feel plastic and wood consumer units were fine, I had a Wylex fuse box for years and so did most houses I visited not seen a single one go on fire, but London fire brigade it seems found some had gone on fire, likely poor fitting and/or design, but knee jerk reaction was metal consumer units. As to if the move was due to BS 7671 or if there is some other law which caused the BS 7671 to include the requirement for metal consumer units I don't know, if it was not the BS 7671 but some other body that required the change, then the "not necessarily mean that they are unsafe for continued use or require upgrading." comes into play, if some building regulation or HSE rule then it may be necessary, BS 7671 may not be retrospective, and it is not law, but it follows new regulations so there may well be a new law which requires it.
So in your own house how will anyone know? Even if it is law, no CPC was OK in 1960 so why have it now? I would not worry unduly about it, but in a rented house that is a different matter, the occupants have no option as to what is done. So the owner must follow the rules, and the BS 7671 it seems in spite of saying it is not law, is to all intense and purpose it is law.