I recently came back from Normandy where I took my metal detector. I found a 29th division M1 helmet at Trevieres and a German M42 helmet at Meautis (near Carentan). The M1 helmet is pretty badly corroded, although the 29th insignia is barely visible. The M42 is in better shape, but with no insignias remaining. Here's the issue. The M1 helmet still has active rust and flaking on the inside and I am concerned that it will get worse. Is there anything I can do to stop this process? Any help would be greatly appreciated.