old trophies

I found a coupe of old trophies at Dads house today and I am wondering if anyone knows how to clean them up with out hurting the lettering?The one I really want to clean is from Lions 1962.It is hard to see the lettering due to rust.I do not want to put too much elbow grease in it as I think the letters wil just come off.I tried never dull.The other 2 trophies are from The Pomona Valley Timing Association at the Pomona Drags.They are cool and pretty clean.I would appreciate any ideas.