Does anyone know where to find photo archives from this film?

International velvet (1978) It's one of my favorite movies of all time

The horse in the film looks identical to mine,and I've been trying to
find more photos of it,but I've had no such luck,
I figured there must be some photo archives out there somewhere,or
some tatum o'neal fan site with rare photos from the film or ANY
photos aside from cover images anyways,if anyone has any
suggestions,or links or whatever,I'd love some help with this.
I've looked on imdb,and all those obvious websites already,but I feel
like there must be some search engine,or photo archive website or
SOMETHING that I'm missing.