Based on all pictures posted on Craigslist, I'm 99% confident it's all original. Mine looks very similar maybe 50% along the way to this level of wear.
It has been obviously heavily played. You can see a few resoldered keyboard posts, worn pearl cups, etc. But that can be a good sign that it's probably a great horn. You should make sure its mechanism is in good order, with not much play on the key rods or any signs of prior heavy damage, etc. I assume you'd be picking it up in person? Fair price for a 157k range VI in this condition., but I'd try to bring it down a little lower myself. good luck!