Always an interesting topic with many different opinions and it is nice to see. I have many M56 series helmets, both in used and unissued condition; always keep them carefully.

For me, whether to restore or not to restore largely depends on your opinion, and how you view your collections.

Another important thing is, how would one distinguish "Restore" and "Preserve"?

Does removing dirt and rust and applying wax to prevent the helmet from further deterioration, sound more "Restore" or "Preserve" to you? Just like the member from the previous said, good soldiers try their best to keep their equipment clean, not only for the honor their gears represent but also for the essentials they combat and live on.

For collectors like us, for example, in some coastal regions, or places with higher temperatures and moisture, Steel pots are easier and faster to be corroded. In this case, how would you choose to keep this "piece of history", whether to leave it and let it go with nature, or do something? If somebody works hard at cleaning excessive rust from a steel helmet, would be understandable to me. Getting cut by a rusty piece(sometimes dipped with dirt) actually brings risks of a sequence of serious health problems, such as tetanus. This is very crucial for helmets with sharp flanges or liners metal loops, such as M56 or M42. From this perspective, there is something more to consider besides "devaluating". Being careful is frankly important, but accidents do happen.

Or one may refer to "Restore" with removing original paint layers, changing all features, etc. All fine so far, but keep in mind that what you have changed may never turn back. Also, think more before you try to do so. I have some M56s, and they were refurbished by either the military units or the factory. The first one often repaints the helmet without removing the former paint layer and applies a new liner at the end. The latter one, which will be a preferable method for me, treat the helmet with professional procedures(acid wash, sandblast, enamel baking, wow...).

It would be reasonable to choose the way you prefer. It is good to keep the past history, but never forget, that people nowadays, all parts of our life, and we are also creating a new history.

Regard
E.K