I was given this shell recently:
So, I bought this liner online:
The label in the crown reveals that it was originally made in 1960 by COGEBI (the Belgian General Insulation Company) for the navy - 'ZM (anchor symbol) FN' is the Flemish/French marking for the Belgian Naval Forces, the equivalent of 'ABL' for the army. It's made of phenotextile resin impregnated fabric, like the US M1 liner type it was modelled on. The outer surface has been sprayed OD over the navy blue textured finish, which shows through here and there. Presumably, this is the result of return and refurbishment at the army supply facility in Ypres. Of course, it could've been done by someone else but this facility is said to have taken in stuff from all the services and turned them around without any reference to from whence they came.
This info I have deduced, with the help of Google Translate, from the excellent Belgian collector's website: casquescollection.skyrock.com/1 (which I expect many readers of this will already know). I hope nothing has been lost in translation......
You can see from these pics what shell and liner look like when assembled with a cover:
I've had the cover for a while. It's unissued and not labelled or marked. I had understood it was a commercial invention that may or may not have been available to Belgian servicemen. However, the website mentioned above seems to suggest that current thinking is that it is more likely to be the product of the Belgian military's supply organisation working 'in-house'.
The second M51 I've had for a while:
Unlike the first example, this one still has it's decal. It's had a quite glossy repaint (at Ypres?) and the Belgian equivalent of the US M73 straps added.
The liner is the later plastic variety. The website mentioned above indicates that these are considered inferior products in comparison with the phenoltextile type. The plastic being known to 'go off' in various ways including getting very brittle. There were various suppliers, this one is Levoir, Belgium. A firm in Hong Kong has apparantly made rather nice examples.
Put together, with a net, this helmet looks like this:
The above website is not the easiest to navigate but is full of gems and excellent photos. I intend studying it more closely........... eg it seems a number of M51 steel shells appeared in a US Army inventory during the 60s..............
Hope this is of some interest.