Sheet music for found HALLELUJAH I’M A BUM!, published by Villa Morét, San Francisco, in 1928 can be seen at the website of Mississippi State University. A blurb on the cover says: ‘As originally arranged and sung by / Harry McClintock / “Mac” / The famous radio and record artist’

The lyrics are practically identical to those posted by Joe Offer above, give or take a couple of “Oh...”s and some punctuation.