Hi there CCG, and welcome to the forum.
I reckon the word 'traditional' covers just about anything. Theses things evolved on an ad hoc basis, so unless you are trying to emulate a particular line or company, you could style it pretty much how you fancy.
Googling for images under 'rail buffer' produces lots of tired looking ones.
My favourite colour scheme is..... 'rusty frame, with oil patches'.
This sort of thing made out of old rails....
http://www.semgonline.com/infrastr/pics/im_buffst-1.jpg
Best wishes, BW