I need some help.

Hi. I have this problem: I bought M1C airborne helmet from http://www.sofmilitary.co.uk/reenactors/index.asp and on the photos the helmet looks good but when it arrived the liner was stuck in the outer shell and don’t want to come out. I pulled stronger and it finely got out but when I want to put it back it doesn’t go well. On the photos in shop it looks like the liner fits perfectly in to outer shell but mine doesn’t. I think it’s because of the rivets, also it looks like the outer shell is a bit small. And it doesn’t have the rivet for leather chin strap. I send some photos. And sorry for my English I am from Slovakia.-- attachment is not available ---- attachment is not available ---- attachment is not available --