Looking at a barrel horse that is appendix and I don't have much experience with appendix bred horses. It appears to be a nice horse, does anyone have any thoughts on this matter? 

I ran an appendix horse for years, she was great.

About everything in the QH breed is actually an appendix, but somewhere a long the line a horse advanced out of it. If I liked the horse, it would not natter at all to me.

Nothing wrong with yellow papers.

Thank you! Has anyone heard of Zevi or Cona Fols? Those are two of the thoroughbred names on these papers. The QH is First Down Dash and Easy Jet, of course those are well known but I've never heard the thoroughbred names. If anyone knows of them or has experience with them, would be interested in your thoughts! Thank you! 

Zevi was a big time cross on QH race horses---I have heard they can be a little on the hot side, but that is just a rumor, I do not have any personal experience with them.

You can do anything with an appendix registered horse that you can do with any other quarter horse. The only problem that will ever arise is that you cannot breed an appendix quarter horse to another appendix quarter horse or breed the appendix horse to a thoroughbred. There are a lot if appendix horses out there running barrels. 

The best mare I ever rode was by a TB, Top Avenger,  a good TB will put some grit on some of the more modern QH lines.  If you see how TBs train vs QHs on the track, you would see why.  There was a lady down here that had a super nice barrel horse that was by a Storm Cat son.  If they are built right I love a lot of TB.