It sounds to me like the shoulder cut is the only option that really fixes the problem, the rest only kind of seem to address the problem. You could try the other ideas, but I suspect you'll have the rib cut performed eventually. Not only will it have a more friendly string length, but the shoulders will be a little more accesible. As much as I hate to see such an old bass getting cut up, I would hate it more if no one used it because it was too awkward an intrument. I wouldn't say I'm very qualified to make such a recomendation, but you asked for our opinions...