You Are My Sunshine (Seagull Merlin) 

Here is "You Are My Sunshine" played on the on the top and middle strings of the Merlin.
Normally you play the tune on the 2 melody strings at the bottom and the middle and top strings sound as drones. I demonstrate this as well in this video.
Here I am thumb picking and lightly brushing the lower strings with my index finger.
The tuning is in the mixolydian mode D A DD
I do not cover this thumb picking in my Merlin music book but you easily transcribe the music from my book.
Go to You Are My Sunshine (page 4) in my Merlin music book:
Where you see 0 1 2 3 you thumb pick on the top (bass) string
Where you see 4 and 5 you thumb pick as 0 and 1 on the middle string.
Lastly, I also demonstrate the use of bar chording (which is covered in my Merlin book) and singing.