Sliphorn King of Polaroo

This cartoon seems to have vanished from the radar screens, along with most of the Walter Lantz material, which is a shame. The basic premise is that a trombone player named Jackson falls overboard and washes up on the island of Polaroo. The trombone solos are played by Jack Teagarden, a great jazz trombonist and there is a wonderful song the denizens of the island sing about Jackson, called, naturally enough, "Jackson, Sliphorn King of Polaroo". It's all great fun and a good time is had by all and sundry. Hans Conreid's narration is just perfect and there are sight gags worthy of the master, Tex Avery. I wish I could see this one again. I don't know why so little of the Lantz output is available. If anyone can tell me, I'd appreciate the information.