This knife was designed for freeing aircrew from crashed aircraft.

It has a cutting edge only on the inside of the blade, the blade tip is deliberately blunted. It is designed this way to enable the user to cut through webbing / harness without injuring the airman.

The leather scabbard has SHEFFIELD ENGLAND on it, the blade has:

HOPKINSON RELEASE KNIFE

The little press stud has gone from the retaining strap, otherwise execllent condition.

I do not know what date this knife is, any info would be appreciated.