I don’t think it’s a repro, it could easily have sat in a depot for decades. As a general purpose tool chest it likely would not be removed from service for disposal like a specific kit would after being made obsolete. The lid suggests it’s been exposed judging by the colour.

As an example, in 2003 I found a spring balance in a kit in a cupboard and it was for testing the springs on the I’ll fated Harrier 25mm cannon. It turned out to be a Vickers/Enfield trigger tension gauge. New, never used but still technically in service.

---------- Post added at 09:48 PM ---------- Previous post was at 09:47 PM ----------

Oh and SE Co must be Sterling Engineering.