I have an antique wood encased copper bathtub that looks as if it originally had grey metal plating, probably tin. The plating is wearing away, and there seems to be a clear brownish coating (varnish?) that is chipping off the areas that are still plated. The tub has seams that appear to be soldered (silver?). The tub is stamped "HENRY STEEGER 16 oz Warranted". Any suggestions for how to make the tub aesthetic and usable?