Nambu -- GI modified

[Long Shot]

Over the years I've seen many of these. Some think the source of clear plastic was from airplane cockpit windscreens. Sounds plausible

+ 1 Absolutely!

[Type4]

I think it was a common practice among the officers, they used plexiglass taken from the planes, in some cases were also doing the grips of the daggers, here the famous colt of FELIX SPARKS