Taylor 12 Double Truss Rod Adjustment Help

[michaelm101]

Thought I'd give a holler on this trusted source of info, as Taylor hasn't gotten back yet.

I have a 1976 Model 755 12-string that I just discovered uses a double truss rod.

From the 1980s until about 2020, I had all my instruments setup by pros, but since 2020, I've become pretty good at truss-rod adjusting.
This one (actually two) is something I've never seen.

1) Were these guitars designed to be tuned down 1/2 to 1 step (I owned a Kottke that was designed for C#)?

2) I plan on stringing this guitar with 8-strings (6, with octaves on the D and G) using Thomastik-Infeld Plectrum.

Can anyone give me the low-down on wrench size and procedure for adjusting this somewhat intimidating, double truss-rod?

Thanks very much for in advance!

[Fathand]

1) Taylor used to guarantee their 12 strings could be tuned to full pitch. I believe that is how they established their reputation.

I remember their ads in Frets Magazine in the early 80s.

https://www.taylorguitars.com/suppor...od-adjustments