Opinion about helmet

[mp40]

My friends wants to know something more about this helmet.
Any help would be nice.

Thanks!

http://www.postimage.org/image.php?v=Tsm0qq9

http://www.postimage.org/image.php?v=Tsm0UlS

http://www.postimage.org/image.php?v=gxVi75J

[Adam S.]

German M18 with reinforced aluminum liner band, postwar liner and perhaps an original chin strap. Paint looks to be wartime.

[tankredi]

Obviously the ventilation bolts have been replaced after ww1 with m35 style rivets.

What is the welded spot on the flank of the helmet? Is there the same spot on the other side?

The spot and the brownish color under the grey make me think that this might haven been an Austrian helmet before the transformation, the so-called Hungarian Berndorfer.

[mp40]

Sorry, what spots?
Are those helmets rare?

More pics

http://www.postimage.org/image.php?v=PqNRFar
http://www.postimage.org/image.php?v=Tsm0vpr
http://www.postimage.org/image.php?v=PqNRge0
http://www.postimage.org/image.php?v=gxVgYLA