The info is first hand from Egginton Bros. and comes from the Sales and Marketing Manager and is in responce to some questions I asked about my Egginton Bros. Fairbairn-Sykes knife which is shown earlier on in the thread.
I'll quote, word for word, the relevent part(s) of the letter...
"We manufacture the Fairbairn-Sykes Commando Dagger here in our Sheffield factory
The all black dagger is supplied in two versions. 180B is our standard version, and 180BMoD is made to Ministry of Defence specification E/1323E and conforms to NATO Stock Number: 1095 99 9632037. Our knives are in use in the present conflict in Afghanistan.
The 180BMoD differs from the 180B in two ways. Firstly, it is balanced at a particular point. We believe this is for throwing purposes. Secondly, the knife is not marked. We are not sure why this is.
Ministry of Defence specification E/1323E demands that the knife is supplied in a Leather Combat Sheath. Again, we offer two types. LS/180 is our standard version. LS180MoD is made to British MoD specification E/1323E and conforms to Nato Stock Number: 1095 99 9632037. The LS/180Mod differs from the LS180 in just one respect. It is made from a better quality, softer leather."
There is then a general bit about the company and who they acquired etc and then the following
"Our standard 180B Daggers are normally stamped on the cross-guard with the William Rodgers name. This company has a long and proud history of supplying daggers to the Commando Regiment."
There is a bit more about when the Egginton Group and then this final bit I'll quote...
"There are daggers sold by our competitors which are marked with the NATO stock number etc which claim to be made to British MoD specification. We would refute any claim to this effect. For a start true MoD specification knives are not marked with anything. Furthermore, we believe the material used in the blades is not per British MoD specification. We have not however recently performed any product analysis to prove this for certain."
So, there you go, make of it what you will, but it would appear that there is definitely a MoD version and a 'commercial' version of the FS dagger going by what Eggintons have said?