Whenever I get a new gun like the one you've gotten I'll fix it up as inexpensively as possible (just enough so it's not an eye sore) and use it for awhile before I decide to keep it or not. With that thought in mind, you may want to simply cold blue the barrels and use it as is this season. If you find you really like it then spend the money to have it rust blued.
As far as cold bluing the barrels, I simply remove any patches of surface rust, degrease with automotive brake cleaner spray and then cold blue right over the old blue. Usually 2-3 repeats with cold blue will get it looking pretty nice.
Steve
