Antique World War I Monocular Restoration - Carl Zeiss Jena

This week I restored this World War I monocular used by the Germans and made by Carl Zeiss. It’s a pleasure to restore such a high quality piece of optics. There is a lot of dust and dirt inside so you can barely see anything through the lens. The surface needs some restoration as well. I decided to leave the eye piece assembled because it was constructed so that I would have had to damage it to disassemble and I wasn’t sure I could put it back together as well as it was. Also I didn’t see any major dirt or other reason inside to give me an excuse to risk it. After the disassembly I cleaned the brass parts with ketchup and then polished those with wool wheels and polishing compound. Ketchup is a great way to remove patina from brass. It contains vinegar and also some enzymes which help with removing the oxidation. It also doesn’t smell and it is readily in easy to apply formula. Vinegar is also more aggressive which could leave to damage to my unoxidized brass. The aluminum sheets or caps