Sounded like a smart a**, I did - I meant to follow up with excerpts from some earlier posts on this forum. One place was this thread:
viewtopic.php?f=24&t=2243&p=20273&hilit=carbon#p20273.
Also somewhere there is positive feedback from Mike Doolin to a letter I sent him concerning this subject, who uses the cf, and Bob Matthews, I think. I'll do more looking around and find those links.
edit to add link to Bob's picture:
download/file.php?id=2698
edit: Here's the thread that addresses it directly - interestingly, both Ken and John P. had, at that time, a positive remark to make about the cf rods directed to the endblock.
viewtopic.php?f=15&t=1622&hilit=doolin&start=0
And an excerpt from Doolin's letter:
"I did use graphite tubes in the Jazz Harp Guitar (also) -
doolin4,5
But there I wasn’t concerned so much about rotation of the neck block as I was about compression of the top, since the instrument has a tailpiece. The string tension translates to compressive force between the neck block and tail block, and the tubes directly bear that compressive force.
All of this is to say, that I think graphite tubes bracing the neck block is a great idea, but I do think they work better when they’re inset deeply into the neck block. When they’re just butted up against it, there isn’t as much preventing the block from rotating forward. This is especially true if the tubes go to the waist, since they’re bracing at about a 45 degree angle to the force being applied. When they go to the lower bout, they’re more in line with the force. I used rectangular bars because they’re easier to glue tightly into a notch cut in the neck block.
But in general, I think _some_ sort of neck block bracing is a good idea, even for non-cutaway guitars. And for cutaway guitars, it’s an even better idea."