Could someone help with the age of this DB?

[westward10]

The protective devices you have are probably BS3871 type C but in some circumstances the white written ones are type 2. You would need to remove each one, type 2 are always printed as such. Some state type C (3871) but if if is not printed assume type C. Crabtree were still producing these up until a few years ago in the guise of 60898 type C they are actually quite rare I've only ever seen one.

 

[timhoward]

Wouldn't you know it. John also posted a video of a C.50 board, albeit a (later?) steel enclosure.

Saw one last week, as above there are quite a lot of them out there.
What was a first for me was finding a 7.5 amp circuit breaker.

 

[westward10]

7.5A is very common for commercial distribution boards. Not quite sure where the rating is derived from I've considered it the BS3036 equivalent of the 5A fuse (apply the 0.725 correction factor gives you about 7A).

 

[Dustydazzler]

When ever I see these older grey metal boards with those black breakers, I think of an American style panel