Reply To: I appears that someone forgot to cut the hole in the sound board strut that bloc

[Matt Hayden]

The truss rod adjustment nut and hole are angled up, so you’ll need to use a 1/4” drive socket with an extension and aim it at the block at an upward angle.  I think it’ s a 3/8” socket.

I’ve not seen an SCGC with a Martin-style hole in the brace.

Here are some inspection-camera pictures of an SCGC truss rod by Frank Ford:
http://frets.com/FretsPages/Luthier/Data/TrussRods/trussrods6.html