Are you looking for a real commando knife or a fake? If you want the real thing, do the homework so that you will not get ripped off, there are far more fakes out there than there are real Fairbairn - Sykes knives. If you don't want to do the research you can get hurt, either price-wise or quality-wise or both. A good place to start:
Fairbairn Sykes Fighting Knife First Pattern
An excellent site with plenty of information. The first page describes the development and the First Pattern, links are provided to the sections on the 2nd Pattern and 2nd Pattern Private Purchase knives and the 3rd Pattern, and on and on. Scabbards are also shown as well as grip variations and markings that you need to be aware of and, very important, post-War production is discussed. Some are not what less knowledgeable collectors (like me) call "fakes" but then, some are..... The linked site will help you. A lot!![]()