I have the same pattern of sgian Scott. Mine is a British military issue item, however, it is (as far as I know) post WW2. I guess that this may be a war-time pattern that continued post-war. Hopefully some old soldier on x-marks will recognise it.

Although the pattern of the handle appears to be identical to mine, with the three grooves and the same characteristic shape, the blades are a little different and mine has no legend on the blade. The handle on mine is plain polished red-brown wood (unpainted) and has a brass ferule where the handle joins the blade. There is also no insignia on mine.