Today I decided to revisit Little Grass Shack and fired up Youtube and searched for the tune and found this:
https://youtu.be/f5VEen_TI_A?si=xd1P6-vBZaNxnHk4
Whoa! First thing was it's in C. Okay, but what about all those jazzy chords? I tried to play the V chord and could not get the voicing. I realized C6 is not working here. Then it dawned on me this has to be Jules Ah See. The tone, the chord stabs, the playfulness, the ease of execution. So I went to John Ely's ""Tuning of the Pros" page and found his E13 and tuned my six string Asher that I had on my lap to the first 6 strings of the tuning. Bingo! I was finding a lot of what he was playing.
That said, there are some passages towards the end that sound like C6 with open strings, like the D9 chord he uses.
Can I assume he played some of this on the C6 (C13 actually) neck and get on with my life