It’s not too hard to Google the name of the horse show + photographer + year. Where you’re going to run into a hard time is that most of the Virginia photographers sort their photos by back number or classes, not horse name, so you’ll have to do some cross checking.
You’re not looking too far in the past, really, so you’re going to have better luck. Here are the photographers I know
HITS Culpeper was ESI until maybe 2022 or 2023. They do not post online. After that was Allison Hartwell (I think). She required a $50 deposit to view online photos. This year (and maybe last year) KMK Photography was there. She does a great job.
Lexington, Deep Run, Upperville, Rosemount, a lot of the “older” shows still use Teresa Ramsay. She changed websites last year maybe? It’s been much easier to find photos from her shows since she updated her website, but if you’re looking for photos from before the change you might be out of luck.
There is another photographer who is kind of “new” on the scene called Hannah Jones Photography. I know she has been at Deep Run as well as some other shows.
I know there is someone I am missing from these bigger shows but I’m blanking at the moment. That should give you a start though. You may be able to email these photographers about older photos but I would be prepared to have to pay for the trouble of finding them for you.
Edit: Erin Gilmore is the other one I was forgetting