Saw the recent IET article "Estimating the age of an electrical installation" which folk on here might find it offering a few handy points. This might work:
However, some folk on here will also know a few more dates/tricks to help identify things!
Estimating the age of an electrical installation
It is often necessary as well as useful to be able to establish the approximate age of an electrical installation, whether needing this information for reporting purposes, work or just plain curiosity.
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However, some folk on here will also know a few more dates/tricks to help identify things!