Look, OP, I'm going to tell you something, because I'm feeling very brave and frisky today, having just had surgery and used up all my vicodin. Well, not all of it, but enough of it. I feel like I'm a bear emerging from a cave in spring(performs tarzan yell).
First of all, focusing on the stallion's record vis a vis how it will make this colt more marketable, is totally and completely beside the point. There are thousands, probably hundreds of thousands, of Arabian stallions at stud like him. The owner isn't any more irresponsible than any of a number of other breeders. They either know their stallion is inferior or they don't, be that as it may, the thing is procreating.
But discussing what the stallion is, or isn't, is pointless. This colt is not a resell project. Not a successful one, anyway. It wouldn't matter if this horse was by the greatest Arabian stallion and mare that ever lived.
This happens. It happens to the best breeders and to the worst. That is not even worth debating, it happens to people with good horses AND bad horses. What is in question is how is this most ethically handled. What is in the animal's best interests, I mean.
Look at the back on the stallion. That stallion is 18. He climbs up on mares or a phantom or both, he has probably been ridden at least part of those 18 years.
Now look at this colt's back.
At 2, without having been ridden, without having jumped any mares, that 2 year old colt's back is lower than the 18 year old stallion's back.
That colt's back is a whole different deal than the stallion's. This colt's back isn't about the length of back or the configuration of the loin, many other horses have same.
This is different; it is about bones that did not form normally, and are not holding the back up in a normal way just for the animal walking around and eating grass for the last 24 months. And those bones will never, ever be fixed. This is a skeletal deformity.
This is a whole different kettle of fish. The stallion is 18 and he's been jumping mares and being ridden for at least part of that time. Of course his back looks like he**.
And I disagree with everyone who has told you tickling that colt's belly, longeing him in sidereins, or anything else, will change that back. That back is going from where it is to more swayed than it is, and if anyone ever rides him, it is going to go WAY lower than it is now. That is the only place it is going. Lower.
You will never sell that colt - as a driving horse, or as a riding horse. Please don't kid yourself and don't listen to anyone who is trying to tell you any different.
There are no sixty dollar bargains around that you are going to fix and sell in a couple months at a tidy profit. A professional trainer or pinhooker with decades of experience doing so would not touch this colt with a ten foot pole. And those professionals who could talk an Eskimo into buying a refridgerator, they are having the very devil of a time trying to sell nice horses with nothing wrong with them these days, let alone something like this.
There are very few horses at ANY price that you're going to turn around like that in a short time at a profit.
And this one isn't one of them. He's got a big knee, and a back that would scare off all but the stupidest buyer, and is that the life you want for this animal? Being knocked around by that kind of person?
Get him because you want a pet, because your horses need a pasture pal, and be prepared for the possibility that he may have to be put down some day, but please, stop kidding yourself that you are going to turn around and sell this animal to anyone.
"Ok Wels, tell us how you really feel"
LOL.