F Pentagon symbol.

My understanding was this mark was only applied to guns sold after Jan 1970 within Germany and that it is/was quite legal for a German person () to own a/any guns without that symbol provided they were purchased before the cut-off date (1971). Qutie why anyone would go to the trouble of stamping the symbol on an older gun for which the German Law did not apply (usually on the barrel breech) is beyond me - maybe it is applied to guns that are later re-sold through the gun trade.

It is not nor has ever been a requirement on all guns Made in Germany just those offered for sale there. Export guns are unaffected (esp. stamped Made in Gt Britain!)

Possible makers

Oskar Will as a company sold out to Vespa (was it, something like that) who proceeded with the Will trade name somewhat until 1945 - there we can assume the whole thing died, certainly did in the few years after WW11, as we know. (so it ceased to be in 1945!).

Umarex was formed in 1972 and does have a 'Perfecta' range
http://www.umarex.com/de/airguns/marken/perfecta.html

What we know

OP has owned the gun for 30+ years

Oskar Will did not stamp the F mark on their guns

Umarex do not make (and mark) guns in 'Gt Britain' although they may have done early in their history, it seems very unlikely given the period in question 1970-1984. Maybe they made a Umarex/Perfecta 76 which appeared in the UK between '70 & '80 but why put an F mark on an export gun and why the 'Made in Gt Britain' stamp

So, lets see if the Midland Gun Company had any dealings with Umarex -
http://www.birminghamgunmuseum.com/i...nd_Gun_Company

Err, NO.