A tubby TB eh? I should snap him up quick, everyone knows that TB's are naturally hard keepers and you simply can't keep weight on them! Soorry pet peeve.
As to the, yeah well, pics are what they are, and they are frozen moments in time, but you do wonder why he isn't square in any of them. Certainly worth going to look and ride him, see how he goes, a horse with a sound mind, who is comfortable to ride is always worth something. After that you have to dig deeper, and with this guy I would dig some more, but some conformational issues would not worry me for a pleasure horse, rather than a serious competition horse.
Certainly have a PPE if you think he is the right one having ridden him, you don't want to be buying trouble, BUT for me, it is easier sometimes to keep a less than perfect horse sound...shoeing, supplements, turn out, less turn out, etc, than it is to keep a perfectly conformed 100% sound horse sane, if it is an idiot.