The chrome on the helmets is beyond me,sorry.For the polished tanks,tell him forget the clear.If he's going to polish them,he needs to bring them to a high polish.When he's done it needs some kind of protective polish like Flitz,or a good coat of wax will last a little while.The backbone area needs to be paint and hard to reach areas will be aggrevating to protect,bit it is feasable.I've had guns I've reworked and left in raw steel in FL's humidity for years with no probs.The trick is a very high polish and protection.Guns are easy because they're oiled down,but.If you need some killer polish let me know.I can get stuff that makes steel look like the next best thing to chrome if you're into the work (and lots of it).You can get a true proverbial 'shave in' finish that's cleaner than a mirror if it's done right.Getting the steel to 1200 grit is real work on thinner steels,and a high polish is even more without making the surface really wavy (mainly from uneven sanding and buffing).If it's an aftermarket tank I wouldn't consider it considering the grind marks they come with.Chroming would be the next best option there if the chromer knows how to lay up and sand the copper (or is it brass) to remove flaws.You could also stop one step short with the nickel coat.Nickel is a little greyer in color and will peel on a piss poor prep,along with being a little softer than chrome,but it's corrosion resistance properties are quite better than chrome.