Colt Sheath Knife

[Lemming]

I acquired this knife around 1976 and know nothing about it. Have done some internet searching and haven't ever found anything so thought I'd ask here. It has "Colt" and "Sheffield England" on one side of blade and Rampant Colt on the other. Knife itself is 10" long.

http://s965.photobucket.com/albums/ae131/TheLemming/Colt%20Knife/

TIA- Mike