An 'older CSX', interesting point, older like when Kirkham as well used to build to 'em 'right', before the 'new age' billet this, modern that, yeah, whatever. Older IS better!
There are a few replicas that you can spot as to make pretty quickly. Classic Roadster/Excalibur, West Coast/Stallion, FFR come to mind. Certain body styles are a dead give away. Others you have to get a little closer but still there fairly easy to spot. Aurora, BDR come to mind in that regard.
Park a continuation CSX, Kirkham, CCX, ERA, Hi Tech, CSX original and others together and it starts to get tough who's who!