M40?

[Lidman]

Thanks for all the advice much appreciated, I have a long way to go but hopefully I will get there in the end. I told the chap that it wasn't for me rather than string him along as there is nothing worse than not giving folk common courtesy.

As much as I agree with you about common courtesy, if this was being offered as an original helmet, the seller deserves no courtesy whatsoever Magneto.
Welcome aboard here mate, stick around and learn all you will need to know, to arm you with the knowledge you will need to pick the fakes from the real deal.
In the meantime, post up potential purchases for the lads here to assess and advise on just like you have done here.
Good hunting.

Brad.