Really good work in the first post, Roo! 
As for me, I can't have a scrap yard on my layout. Why? I model the WW2 era. Anyone with scrap was strongly motivated (as in made to do so by law enforcement) to sell at the frozen scrap prices during the war. There were some who tried to hold onto their "horde" of scrap but were forced to sell for what were in effect bargain-basement scrap prices dictated by the OPA. Countless historic artifacts (such as church bells, civil war cannon barrels and plenty of WW2 artillery and tanks form parks) were melted down in the most tragically misguided horror upon the historical preservation movement. None of this was ever used for its intended destination; to be used for defense purposes, as the metal content couldn't be confirmed, so much of it was destroyed just to make the locals feel good about themselves, and then never used.
So, knowing this, a junkyard on my layout would be quite historically incorrect. It's a shame as I'd love to model one...
