I did learn that one some time ago and if i am not mistaken i think you have to change the tuning on your 10th string to get that exact lick, lowering it.
I thoght there was a guitar playing a low single note line along with the steel and doing the wa-wa-wa at the end of the phrase. Now I'm wondering. Who originally did this with Vern?
Jim Vest played on this record and has done most of Verns sessions. The tenth string has been retuned lower and i think it is an A. It has been so long since I've tried it I don't remember.