We get the odd one, got one this year. Usually they manage ok, and as long as they can stand and walk on all 4 legs then Trading Standards will be okay about taking them to the abbatoir when the time comes.
I have heard one farmer say he was asked to sign something at the abbatoir to say the lamb had always been like that, presumeably to absolve the abbatoir of being thought to have broken its legs or something.
We sell most of our lambs deadweight, some in the ring, rarely a few stores, and some go directly to our nearest abbatoir for our local butcher. Any bandy-legged ones we would only take directly to the local abbatoir, we wouldn't put them through a ring or long journey to a processing plant. So far there's never been one the butcher wasn't happy to have - and there doesn't look to be much wrong with yours apart from his bow legs! - but if there were we would just have it for our own freezer.
I have a personal theory that the deformity may relate to a mineral deficiency in the ewe - certainly the one we had this year was a triplet from a ewe that had missed her usual mid-pregnancy mineral drench (with chelated copper) and is a type of ewe that does need her minerals, including coppper.