I’m going to explain in technical terms why the ending is unlikely to ever turn up:
This was a cut before release, and was cut off the original SEN and Track Neg. The only way it would likely exist is a workprint in Warner’s holdings. For the past 50 or so years, Warners has kept all their holdings of the cartoons at UCLA’s holdings, and such a workprint would’ve been labeled as one, like the case with Crackpot Quail. No such print exists, and in Warner’s own vaults, no prints before the release exist either, unless one is mislabeled. This is one case where I think the subject is permanently lost, but I would love to be proven wrong