A set of decals: the white palm tree with a swastika and tricolor shield (black, white, red). The palm tree is 44 mm high. Price per pair (set), not sold separately.
How to install the decal? Put a piece of paper with the image (as it is, do not cut anything) in warm water for 30-60 seconds. If there are advertising elements on the decal (logo or frame), they are easily removed (with fingers) when the substrate is wet. After that, the decal must be put on the surface of the helmet and, holding the image with your finger, pull the paper base out. Set the pattern evenly, wetting it with water if it sticks. You can pre-mark the surface of the helmet using a pencil, where the corners of the picture should be. Then remove the water from under the picture with a rag or toilet paper, holding the image with your fingers, so as not to move.
How to fasten the decal? The decal keeps perfectly by itself and does not require fastening. However, if you are going to wear a helmet during reenactment and make it wet in the rain, the decal must be additionally fixed.
1) A well-dried image can be varnished. Areas around the decal should be masked before varnishing. Varnish is sold as aerosol in stores for artists or motorists. On original helmets the lacquer over the decals was usually gloss and covered the decal area plus 1-2 mm from the edge.
2) Another way is called "baking". It may not give a good result from the first time (the decal may swell if there is air or water droplets under it), but if the result is successful, the decal holds so firmly that it can only be removed along with the paint. It literally melts into the paint and becomes one with it. To bake the decal, you need to heat the helmet in an oven (gas or electric, not microwave!) untill you can't normally touch it with your hand, but not more, so as not to burn the paint. Then turn off the heater and allow the helmet to cool down.
Was there such a decal? Most likely yes. Commercial firms produced a lot of small goods for the soldiers' shops. Were they officially applied? Probably not. Usual emblems of the Wehrmacht, Luftwaffe and SS were on the helmets of the German African Corps (Deutsche Afrika Korps, DAK).