The Mystery Vader helmet

Does anyone know what vader helmet this is? I know its not fan made. 20th century maybe?
I mean this particualr casting is fan made but was cast off a production helmet.I got this helmet about 5 years ago from someone in a trade.They didnt really know what it was either.I just dug it out that why the resin is all yellowed.It has no coupler attachment for the head and dome but that could have been whoever molded it didnt know how to do it.It also does not have the half moon indents on top the the cheeks like most vader helmet do.

Bondo Stealth Trooper

OK so Im down to the nitty gritty on this helmet.Mostly sanding and minor pit filling and a few more syymetry issues.I wanted to have this done a couple weeks ago but I got sick of looking at it and had to take a break from it.Here is a pic of where its at as of tonight.

Making Stealth Armor Parts

So I decided I wanted to make the armor as well to go with the stealth helmet so i have begun to make the chest plate and chest box.

Basically i covered a mannequin with some plastic wrap so if i slopped bondo on it it wouldnt ruin it.
I then used cardboard and made a template of the main parts.I then coated the templates with bondo and am now sculpting in the basic shape of the armor/chest box.
I then took a piece of sintra(sheet plastic) and figured out button placement.I sculpted 1 button out of bondo and made a mold.I then casted 3 buttons out of that mold so they are all the same.
I used a exacto knife and carefully cut 3mm strips off wooden tongue depressors and used those to make my raise out line around where the buttons will be.
I made some changes to the length of the chest plate and now am using bondo to sculpt in the details and contours of the box and chest plate.
I will also be making the shoulder armor as well and possibly the back plate if it turns out to different than a standard back plate.