That is true and I did that once with head light buckets and filler tube. The problem is getting someone to galvanize it smooth. Most shops will return it with a very rough finish and all the holes/threads will be filled up as well requiring drilling and tapping. I still had to tumble it after to help smooth it out. It was a lot of extra work but looked good in the end. I think the stampers used pre-galvanized sheets before forming the product. I know this is true with Chebby disc brake backing plates. Most here would be happy with tumbling originals - they actually turn out pretty nice.