Older Small horse Beginner Novice Eventing?

So, I just asked what you thought about a pony eventing BN. What about this horse. He's 14.3, 15 years old, and used to be a hunter jumper. The owner was told he's a quarter pony, but be has the body of a TB and the face of an Irish Draught. She said he jump very well. He was just injured pretty badly today. His muscle skin and muscle were cut. It required stitches. It where the girth goes so he won't be ridden for a few months. It won't affect him after it's healed up, but anyway. What your opinion on that. I'm have lots of experience when it comes to young horses, but I can't tell with theses old and /or small guys. He;s very sweet, and I'm sure he float around the dressage ring and over jumps. Thanks, no rude answers please!