Old shield

[Andrew]

Originally Posted by Robert

Hello Multumesc, Personally I would clean this in warm soapy water to remove as much dirt and powdered rust as possible then dry thoroughly. On an item like this where no wood or other organic material is present I would place the item in an oven at 200 deg F for about twenty minutes to make sure that all the water has evaporated. After it cools I would use a light weight oil (like sewing machine oil) and 0000 steel wool to remove any loose rust. Wipe with a clean rag with a small amount of oil on it until all excess rust has been removed, then wipe with clean dry cloth to remove all excess oil and lastly apply a coat of Ren wax and polish. This is what I would do but others might have better suggestions for cleaning.

Best,
Robert

P.S. Please do not make it shiny, only remove the dirt and filth and stabilize the rust.

This. I strongly suggest avoiding any etchants (acids) like vinegar, cola, fruit juice, naval jelly, etc. This item should not be aggressively cleaned or polished unless you want to destroy any collectible/artifact "value" or intend to fully restore it.