A skilled, professional woodworker, that is...
not the weekend warrior woodworker hobbyist. And there is a BIG difference in the price of a coping saw and an accordion!

The original question was of the POSSIBILITY...not PRACTICALITY. The original poster got the answer he was looking for, "yes, you can play a little tex-mex sounding stuff on your one row for variety's sake in a gig without buying a whole new box for one or two songs." He listened to the recordings I referenced and liked what he heard and was satisfied.

You are right you can not do EVERY third like on a triple row, but by "mixing" the thirds and sixths I posted you can sound pretty dang convincing on a very simple song in the key of the box. I played in TX with Kingfish when I was kind of dabbling with the tex mex sound in our music--but I did not have a triple row. A triple row player in the audience asked to see my accordion...he asked "Where's the other buttons? You're making all that noise with one row?!" He said, "It is much easier with more rows!"

Since a friend loaned me a triple row, I can see how right he was. But the triple row is a monster in many ways because you can play the same notes in so many different ways!

I would not start a Tex Mex band with only a single row accordion, don't think I would get very far! What I was trying to say or to demonstrate is possiblities of playing a tune on the single row that suggests a tex mex sound or style.

Let me know if you find the time to try out all the intervals I demonstrated. I think it is "cool" because it might inspire someone to come up with some new licks for Cajun tunes!