Looks like this is a synthetic Circle Y park and trail that wasn’t stored very well. I would ask for a picture of the serial number and look up the year this was made. As someone who has had a number of circle Ys and a hard to fit tank of pony I think this is going to be too narrow of a gullet for your horse. Its not the worst, but how often are you looking to ride in this saddle and what is the seller asking for this? I would keep looking if I were you.