As you're finding out the repro chrome items are less than satisfactory,my own rear tail-lights and brackets have rusted badly in a short time too.
Our councils love of road salt in the UK doesn't help either,even if you don't use your truck in colder weather i'm pretty sure there must be residual salts etc on the roadsides even after a while.
My stainless (original) hood emblem is on the other hand perfect.(At least as perfect as its 64 years will allow!)
So from that I would deduct,stainless is the way to go IMO.
