I don't recall seeing gold plated triggers on anything other than the highest grade Smith guns; but barrels are another matter. I've seen a Grade 5 and a Pigeon Grade special ordered with Whitworth barrels; and I'm sure there are many others I haven't seen. What we see more often is a higher grade gun fitted with a secondary lower grade barrel set such as an A-3 with a secondary Nitro Steel barrel set, an A-1 with a secondary OO Grade barrel set; and I've seen several others, those are simply the first two examples coming to mind.