It's an M16. I am not quite sure which SS troops used these exactly and had a lott of discussions about it with fellow militaria-collectors. I've read and heard about several uses for this type of helmet: combat helmet for SD, parade helmet for SS-VT, pre-war austrian SS helmet...but untill this day I haven't been 100% sure who in the SS organisation used this type of helmet. It used to have a NS-party decal on it as well, but it was removed by a previous owner , you can still see the outline of the decal. Also the decals were applied reversed but I don't know the purpose of this.
The other one is your typical M42 single decal SS combat helmet .
This is a pretty well known picture. The 2 on the right are wearing the M1934 medium duty helmet while the guy on the left is wearing a World War 1 M1918 helmet. The use of the M1918 probably had something to do with supply shortages or maybe he's just wearing it because it provides better protection than the medium duty M1934, at least that's what I've read about this picture if I remember correctly.
Why do some of these SS / Waffen-SS men don't have the SS runes on their right collar patches?
In some countries owners of pictures with SS symbols have criminal prosecution. And these owners paint over SS symbols on photos, pic or some..... We see that on last photo. The owner has shaded SS on photo.
In fact..., in Russia it is forbidden image SS on public. This penal (but sometime).