The following folks are in the Orange hall:
Ted, the fellow who sells all sorts of replacement screws for Lionel
Jill Sisco - bulbs, and other select parts
Town and Country Hobbies - bulbs and other select parts
Ralph the bulb guy - bulbs and dyes to color your own bulbs
George Tebolt - a very limited selection of what he carries
There are plenty of other parts folks in the Orange hall and some of the other halls too.
I very rarely buy parts at York, the booths can be crowded, and time is too valuable to wait around. I prefer to buy mail order.