[Harry Katyn]

Can anyone offer me any advice on how to date French Cloth Modele 45 Arm Badges if it is at all possible given that they have been around for so long?
I have a number of French Foreign Legion examples that I would like to date. I believe that the type of uniform fixing can give a rough estimate. The 1st photo gives what I believe to badges in chronological order, (although some fixings may have run concurrently) –
Sewn directly to uniforms – although used right up to today.
Small press studs.
Rounded hooks.
Flat hooks.
And finally the butterfly clutch back fasteners and the hook and loop variants – (Not shown).
The Legionnaire 1er Classe example with the brown stitching is similar to an example shown in Guyader’s book on the Legion in Indochine Pg.176 but there is no indication what the badge backing was like or how long this style may have been worn for. The other badges in this photo range in different manufacturing methods and may be modern but I would be grateful for any advice.
Thanking you in anticipation.
Dean