Geoff Kaufman sings more-or-less the same lyrics Richard posted. Here's my transcription of Geoff's recording.
https://www.youtube.com/watch?v=Ny6VWokn_ZE

YOU'RE NOTHIN' BUT A HUMBUG
(as sung by Geoff Kaufman)

You're nothin' but a humbug
So they say, so they say
You're nothin' but a humbug
And that's all I know

There's a catfish growin' on a huckleberry vine
So they say, so they say
There's a catfish growin' on a huckleberry vine
And that's all I know

I said, you're nothing but a humbug
So they say, so they say
You're nothin' but a humbug
That's all I know

Well Dandy Jim from North Carolina
He come home for to marry Dinah

I said, you're nothing but a humbug …

Well I never seen the like since I been born
Sailor on the fife-rail crackin' out corn

I said, you're nothing but a humbug …

Now, the blackbird said unto the crow
Why do you bother that farmer so
Well that's been that way since Adam was born
Scratchin' and diggin' up farmers' corn

I said, you're nothing but a humbug …

Now, the blackbird unto that crow
Don't tell the pretty gals all I know
So, it's hoist her high and hoist her dry
Hoist her high for a bulgine pie

full chorus twice