Flaws in a Mk4-5 Helmet

[combathelmets247]

Good afternoon Gents, This brings my tally to 29 Mk4 &Mk5's, When i saw it on ebay it was via my Iphone so the pic was small and i was thinking the Hessian was a later addtion but its Bonded to the shell and rust has bled through the top. Whilst Having a rummage for dates on the shell,Which i cant find any. I notice a few flaws in the shell itself, the top screwis the flathead type. Has anyone else seen such Flaws and could anyone Hazzard a guess at the age IE will it be a 45 made helmet.. The sock is dated 80 and liner band 79

[Composite]

Not seen distorted 3s, 4s or 5s before

[combathelmets247]

I did place the cover back and Corrected the liner, I kinda feel like i should remove the hessian so i can see the ripples in the metal...