You're certainly not bugging me Mark

I'll help if I can
The scale of Sheffield production was massive during WW2, with every company entirely on 'War Work', so bearing in mind the sheer numbers produced, there is probably more chance that your knife was produced during WW2 than since. Of course, "If wishes were horses..."

With the end of WW2, the cutlers were all tooled-up to produce the patterns they had produced during the war, and also, there must have been a huge quantity of stock (parts, materials, and completed knives), which is one of the reason the Sheffield cutlers still produce a number of WW2 patterns, and related ones. Even today, WW2 clasp knives are still a common sight on market stalls and at junk sales, and when I was a kid, every boy had at least one, and they were commonly found in tool-boxes and garden sheds.
The knife below is a knife which was produced in Sheffield after WW2, primarily to sell to conscripted soldiers ('National Service' went on until the early 1960's) in Army canteens (or NAAFIs -
https://en.wikipedia.org/wiki/Navy,_Army_and_Air_Force_Institutes).