Get yourself a silicone rag and wipe it down anytime it' s handled. You can also get a silicone impregnated sock and keep it in that.

Don' t use too much oil on them. I don' t oil anything on my guns anymore except moving parts. Oil tends to attract dust and dust can absorb moisture in the air and hold it against the metal.

Don' t waste your money on the pens. I' ve tried them and they stink. Either get a blueing kit, or take it somewhere and have it done by a good ' smith that knows his stuff. He can make it look like new.