David, are you sure the original 4x3 version of Lady and the Tramp exists in a useable form? The UK "limited issue" release of the film was 4x3, but to my eyes it seemed to be Pan and Scan (although I have only seen it once and could be wrong). Why not use the 4x3 print? I understand that...
Well I've just ordered Jungle Book from HMV.co.jp (see here) (you can click on English at the bottom of the page). Although information is scarce on the Jungle Book release, other Japanese Disney films include the original English soundtrack with no forced subtitles. It's pricey sure, but...