As a regular e-bay advertiser, I thought that I'd just put a very rough guide together for the "new" collectors of M series Stahlhelm.
There were THREE basic combat models. The M35, the M40 and the M42. The way to tell the difference is really easy.
The M35 has a RIVETED air vent and a "rolled under" rim.
The M40 has a PRESSED air vent and a "rolled under" rim.
The M42 has a PRESSED air vent and a 'raw' rim, giving the impression of a more 'flared' profile.
COMMON FAKES. The West German police used helmets very similar to WW2 combat ones and I've often seen these advertised as such. The easy way to tell is the air vents. On West German helmets, they are much larger than M40 items. Sometimes it's difficult to see from a photo, but it may be worth enquiring as to the authenticity-assuming the seller knows of course!! Another common chestnut is the "alloy parade helmet"-this is usually a German Fire Service one with the "pepperpot" vents filled in and a thick coat of Grey paint. The serial numbers DIN-14940 stamped in the rear neck give it away. I saw one at a recent event and the stallholder said to an unsuspecting customer "of course it's original-it's stamped 1940"!!-beware. Talking of authenticity, a few people have commented that completely restoring a shell amounts to a fake. My own views,for what they are worth, are these. If your shell has at least 80% ORIGINAL paint, leave it!! A good coat of furniture polish will protect it indefinitely. I've seen shells at Arms Fairs, rusty as hell with 10% paint described as "original condition". A stahlhelm was never originally rusty, was it? The 10% paint may be original but the rust came from the 1950's/'60's/'70's etc!!
RESTORATION. I've restored dozens of Stahlhelm over the years and there is no easy way of getting a perfect result, apart from hard work. If you can get the shell beadblasted, do so-it's worth it. At the time of writing, there are the last few M35 shells coming from the Czech Republic, ex Czech Fire Brigade. These have had a few coats of paint and, if not rusty, are better stripped with a GOOD paint stripper. As to the colour, I'm fortunate as in a previous life, I was a paint re-finisher at a Rolls-Royce/Bentley dealership and so I know a few trade tricks.
If you have spraying equipment and good neighbours, a matt cellulose finish is really the best. Matting Agent is available from good motor factors but it's not cheap!! Added 50/50 to the colour and THEN thinned, it's hard to beat. Feldgrau is not hard to duplicate-if you have some Blue Green and Yellow, you're halfway there. When the shell is primed and sprayed, "ageing" can be acheived by GENTLE "stroking "with wire wool and then a light polish with furniture polish. When you fit your liner and band, if it's metal, use a little butter at the sides-it'll eventually dry, unlike oil, grease or lubrication spray.
If you dont have spray equipment, I'd recommend a trip to the Hobby/Model shop and look at the Tamiya range of aerosols. Most arm of service colours are available.
DECALS: I buy most of mine from dealers in the USA-the quality is better and they're not expensive. I have some really thin ones which are the type sold at most militaria fairs for a couple of pounds each. These look really good on "aged" helmets-especially with a few tears or cuts on application.
When you paint your shell, make sure it's warm: ambient temperature is fine, but if you're in a damp lock-up, try this. Before and during the painting process, warm up the helmet with a hair-dryer on low setting. This helps to avoid "water blistering" and "blooming"-a white covering of the paint caused by hot/cold temperatures mixing.
HELMET PINS: Dont forget to paint these at the same time as the shell. I usually stick the prongs in Blu-Tack and secure them to a thin cotton line to spray. Try the gun pressure first: too much will blow them into oblivion!!
I hope that this guide will be of some help to someone. I'll give advice to any one who's struggling in their restoration or if it gets too much, I'll always quote for a respray to bare Stahlhelm shells.