Cleaning of chain mail armor and helmet

[sabrigade]

A few months ago I purchased a set of armor used in the Sudan from a Sudanese collector. After the usual permission was obtained from the Sudanese Director General of Customs,I moved the set to South Africa a while ago where I have put it on temporary display in my collection. The helmet shows signs of gold plating etc around the rim and the nose guard appears to have a brass end piece. Any suggestions or ideas on cleaning,removing rust and preserving the items?