Again, looks like my post of this afternoon was lost in the move.
I'd be very careful about using ANY polish on a blued gun.
Scratches in the bluing are just that....scratches.
As such they cannot be removed without damaging the blue.
ALL polishes contain abrasives, and even very fine polishes like Flitz can and will damage the bluing.
I recommend cleaning all old lube and dirt off with a good solvent, then waxing the metal with a good grade wax like one of the "museum" quality hard waxes.
Some people use Johnson's Paste Floor Wax.
I don't recommend auto wax, since many of them also contain abrasives.
Bottom line is, once you put a mark or scratch on a blued gun, it cannot be "removed" by anything short of a complete refinish.
All polishes "remove" the marks by thinning the REST of the surrounding finish until the mark more or less blends in.
Generally guns don't need to be "polished" just cleaned and wiped down with an oiled cloth or a cloth treated with a silicon protectant. This will prevent any rust from forming in the areas where a nick or scratch (which are inevitable if the gun is used) has occured. If the scratch is deep or wide a dab of cold blue may be needed.