Removing rust from GI WWI magazine, how to??

Going through the lockers, and found two magazine with some rust on the feed lips.

Was there a recommended procedure to use??

Thanks.

0000 steel wool and lots of oil,

or a brass brush,

the brass brush and oily rag would likely be period correct

Change the 4/0 steel wool pads often. The iron oxide (rust) is very abrasive, so keep a clean pad.