HuwG, Dana Robinson says his "Pat Do This" comes via Jeff Davis.

"Pat Do This" is a greatly reduced and interesting fragment of the more well-known "Paddy Works" item. It was collected in Nelson County, Virginia from Florence Fitzgerald by Maud Karpeles in 1950. (See this thread about those recordings, currently available from FolkTrax.) It was recorded on Jeff Davis's and Jeff Warner's excellent album, Two Little Boys (reissued on cd on RainDog Records, RD-102, 1994). I have also heard a couple other recordings that don't acknowledge Jeff, but their versions come from Jeff Davis, one way or another, because they include the verse he wrote.

On the banjo it falls into a G-modal, "mountain minor" (gDGCD) tuning. (Sorry, from there I couldn't say precisely what the chords are!)

Here's the text for the Mudcat record:

Pat do this Pat do that
without our shoes, without our hat,
nothing in the world but an old straw hat
to work all on the railroad.

Chorus:
Ruga shugaroo, shugarugaroo,
Sugar in the cream jar, how do you do?
Just on the railroad, folla folla ray,
Johnny comes a-pickin' on the banjer.

In eighteen hundred and forty two,
I didn't know what I should do.
I sailed across the ocean blue
to work all on the railroad.

In eighteen hundred and forty three,
I sailed out across the sea.
I didn't expect to see poor me
a-workin' on the railroad.

In eighteen hundred and forty four,
I landed on this foreign shore
I didn't expect to see me more
a-workin' on the railroad.

additional verse by Jeff Davis:
Railroad Don/dawn (?), we'll take a ride.
Here we go side by side,
Here we go side by side,
Johnny comes a-pickin' on a banjer.

Sure wish I could pick it as well as Jeff D. does.

~ Becky in Tucson