Following is how I use Alclad. First apply the gloss black, Alclad have there own gloss black ALC 304 but any enamel gloss black will do the trick, must be an enamel type paint, lacquers just don't work.
After the black has dried I then airbrush on their Alclad Clear Base ALC 303, it's a gloss clear designed to be applied after the gloss black has dried. This really leaves a very high gloss surface for the Alclad chrome, I then just mist the chrome on at around 15 psi on a 45 deg angle.
Alclad also have a clear that's designed to be a sealer coat over Alclad chrome. It's called Alclad Aqua Gloss ALC 600 this has a milky color in the bottle.This is designed to be applied after the chrome has dried, and makes it easier to handle without fear of the chrome finish being damaged..
Known as a "Bull Bars" in Australia, Not as common as they use too be unless you're running in the out back. Now can get the same protection with a reenforced bumper bar . The one in the photo is a total "Overkill" looks kinda' dumb to me !!!!
Check out Titchy Train Group, HO scale, NWB & riverts, they come in plastic,from memory 20 to a card. I think I got the .030 size, I just sent him a sample [KW sleeper door] and asked him matct and send.
As well as riverts there's bolts,washers, hex head bolts etc. gave me excellent service, to Australia.
You mention that you're going to need a ton of them, good luck drilling all the holes in a straight line to fit the riverts into