Ah, that stupid snap. The first thing I do is chuck it when I get a new backstrap from Ozark! LOL. Should fix a lot of your problem and the rest can be addressed by punching more holes in the crupper straps. Looks like the breeching is about the right length for his bum and you have the height about right...the holdbacks look like a good length. You'll probably find the hip strap is pulled forward when you get the backstrap shortened up, which is a bit of a bummer. His browband appears a bit tight and uncomfortable, you may want to exchange it for a longer one. Can you post a picture with the breastcollar so we can check that? That's often the hardest part to fit and if the traces aren't right you'll need to exchange it before you can drive.
It is a saddle without sliding backband and with wrap straps, not for trail use. This type of setup is used in the showring.The main reason for using wrap straps is to replace britching and sometimes even to pull the cart from the saddle.
If you decide to keep this harness you can use it but I would just use it with the wrap straps through the tugs and not or only loosely around the shafts. That way your horse can move without jarring the cart.
I'm with Jessica here, this is a perfectly fine trail harness and I used one just like it from Ozark for years. Yes, a sliding backband is BETTER over rough ground. Yes, open tugs are BETTER, especially with a well-balanced cart. But properly adjusted wrap straps (snug but not tight) are perfectly comfortable and vastly improve the ride of a not-quite-perfectly-balanced cart like most EE's for both horse and driver. I tried putting the wrap straps just through the tugs once thinking self-righteously that surely that would be just like open tugs, and OMG!!
Never again! Kody begging me within minutes to stop and do them up properly as the cart was flopping and slapping all over the place. Drove us both nuts!
Nice leather wraps will stretch and absorb a lot of the jolting without transferring it to the horse too much unless you cinch them down way too tight. The shafts can still float up when your weight goes in the cart but they're held in place by the leather so they can't oscillate so much and irritate you both. I base my opinion on that of my horse, who never hesitated to let me know when he felt something was uncomfortable or not up to his standards.
Kody loved his Ozark harness and is still very happy to have me put it on (wrap straps and all) after driving in his sbb/open tug ComfyFit harness for years. He likes the soft leather and how light it is and doesn't mind the wrap straps at all. He DOES mind driving the EE in the much "better" trail harness because the shafts bounce and the draft is too high. He'd rather wear the Ozark saddle for pulling that one.
Does the saddle have decent padding and a gullet or does it sit on his spine? If it is not rubbing his spine you might just lose the fleece, it is making the saddle sit funny and tilt backwards. This issue will be lessened when the fleece is broken in and not quite so fluffy, but unless you really need it for his comfort I'd do away with it.
I think the fleece is pretty much a necessity with Ozark saddles. They're better padded than most mini harnesses but nowhere near enough to keep the check hook from rubbing against the spine especially with a load in the tugs. I think most of the awkward angle is because the saddle was sitting too far forward in those pictures and was up on the withers, tipping it back. Should be much better once properly positioned!
Leia