I think you can forget about ever seeing it on DVD, unless you want to master it yourself. I know you said NTSC, but I understand that there are decent-quality PAL copies of it floating around from Disney's last UK release about 15 years ago. Might be worth scrounging around eBay or the like to see what you can turn up - PAL-to-NTSC conversion isn't very expensive, and might be the only way you can get a decent copy.