There was only the Wilkinson Sword logo and the FS logo on these knives.
There were NO OTHER marks during World War II production on the Wilkinson F-S knives.

Knives marked with the Wilkinson Logotype and F-S etching have NO inspector's marks or Broad Arrow and NO letter or number.

For some reason, the FS knife was not considered a Small Arm and therefore did not come under the jurisdiction of the CISA (Chief Inspector of Small Arms), Ordnance House, Enfield.

This is confirmed by this letter  by John (Jack) Wilkinson Latham at Wilkinson Sword Company in his answer to a circular from CISA dated 9th Jan 1943.

Courtesy of Robert Wilkinson Latham

There are different types of etching logos with minor differences used. Here are two different.

 The logos were made by wax pressed on pieces of paper. The paper with the wax was then pressed onto the ricasso before etching. The wax protected the steel and left the letters and logo raised.

To the left a WW2 1^st Pattern F-S knife and to the right a 1^st Pattern knife from 1990.

Paper used for etching of the Wilkinson Sword Company F-S knives.

The normal FS etch on blades was done by women who were usually wives or daughters of men working at the factory.

Courtesy of Robert Wilkinson Latham

Unusual etching

There are several variations of the logo type etchings on Wilkinson Sword F-S knives. It also happened that Sword etch pattern was used. These varied slightly from etching plate to etching plate depending on the regiments, blade type etc as they were all hand done and the design as never ‘regulated’ by the Government. Different makers different designs but they are all similar.

When names or initials were put on FS blades they were normally put on Finished knives but sometimes when knives were not available from stock, the FS etch AND name were done at the same time.

Some of these women used to work pre war in the razor making department. They supplied the FS transfers from the Sword department. When a name was put on, this was done by the Sword department as it was hand lettered usually on a finished blade or knife.

This knife has a very unusual etching as you can see. Robert Wilkinson Latham told me what most likely happened to this knife. In this case all the blade etching was done at the same time and the Sword department pulled of a transfer from one of the sword blade plates, cut it down, added the same pattern as a top piece, trimmed it and painted round carelessly with acid resistant paint before etching. This etching of this knife is unlike the normal FS etch, this made up logo has NO border. It’s just one of those odd things that happened in wartime by someone not used to etching FS blades.
Here are the different etchings used by Wilkinson Sword Company 1936-1945
Sword etch 1936-40	Sword etch 1936-40	Sword etch 1940-46
Courtesy of Robert Wilkinson Latham
F-S etch 1940-45	unusual etching	Sword etch Cut and toped

Note that the top three are Sword etches, while the bottom left is the basic type of etch used on F-S knives.

This etching of this knife is unlike the normal FS etch, this made up logo has NO border. It’s just one of those odd things that happened in wartime by someone not used to etching FS blades.

There are also knives with etching only on one of the sides. Again it should be referred to the human factor. These people sat all day long putting on transfers and sometimes forgot the other side!

Different etchings.