Very Rusted Firefighter Helmet Restoration

This is a very rusted helmet for Firefighter, made in France in 1920. I found this helmet at flea market, cost me 20 euro. As you can see is in a very bad condition, i think is better to restore it than to leave rust eat the metal. I am a not a profesionist to restoration so this is why i buy cheap stuff to restore, like that i gather knowledge. I hope you like it. Napoleon Bonaparte reordered the various fire fighting organisation in Paris (and later other cities) into a unit of the French Army called the style of helmet was widely copied across Europe and beyond. Index of operation and materials: 00:00 presentation 00:40 begin disassembly 0:46 preparing for remooving rust 02:46 cleaning rust with sodium bicarbonate and hard sponge 04:05 straightening the helmet 04:40 grinding the helmet 05:36 sanding the rust from inside 06:00 degreasing with alcohool 06:17 anti-rust primer 06:37 filling spray 07:13 sanding the prim