USMC M1 FS/FB helmet with cover

[Tomasz70]

I have picked up such a nice untouched set recently. As you can see it's all together WWII Marine issue with so called first pattern camo cover. 

What interesting is the number painted in front of the steel pot - looks like D115.

I tried to decode this with assumption that it could be 15th Marine Regiment, 1st Battalion, Company / Battery D. 

Could you kindly confirm my supposition or provide me with better idea?

Anyway it would be great as well to identify the original wartime owner as his name was stenciled on the sweatband - RUST (looks like preceded with T in one place). Maybe knowing the unit it would be easy to find him within the USMC Muster Roll...

Hoping to find your assistance, Tomasz

[Tomasz70]

This helmet was an estate sale find from Columbus GA near Fort Benning Army Base. I know that some Paramarines were trained there but undoubtedly it has no connection to this fact, has it? ;)

[elh1311]

Can't really help you in the OD, Marine helmets aren't really my area, but it's a killer looking set. 

[mdk0911]

first - nice camo cover but I would recommend to NOT take it off - I'm not so sure that the cover is original to the lid.

[Tomasz70]

Cover looks pretty fitting to the helmet. Contrary to my two other covers has no rust spots and the helmet is in very good condition - it was definitely well stored.
Anyway, what most interesting to me is the stenciled number on the front. As you can see it was done on the primary, original paint layer and not covered with second Marine green vehicle paint.
Does D115 stands for 15th Marine Regiment? Then the most important moment in history of this helmet would be Okinawa 1945 and ending of the service in 1946 (maybe in China as I have found some info that the unit was transferred there?).