From what I can tell, any hard case will protect your violin pretty well- Just try to avoid throwing it off trains. I keep a shoulder strap on a hard case, so that if I'm getting off on the fly I can just toss my pack while keeping my violin attached to my body.
As for the old antique-y cases, I've seen people anchor metal loops for shoulder straps that you could pick up at any hardware store.
Wayward- If you love the thing, take it with you. Your instrument will keep you sane, it'll help you make friends, and most importantly, it'll feed you AND get you drunk! If you already know how to play it, I'm sure you can keep it safe, too.
Tare- on the off-chance you haven't gotten a case yet, the answer is no! Make the dough, trade, whatever, to get a hard case.