Some time ago I thought I had a crack in the neck of my RB75. I couldn't really tell. At minimum the Lacquer was cracked. I decided to take it to my Vet and ask him to X-Ray the neck for me. He did and didn't even charge me! Great Vet, but then again he gets it back on my three dogs. Anyway, as you may be able to see, the neck was not cracked. However, I had no idea how thin the wood was around the neck. If you look close you can see the cavity under the coordinating rod cover. Then see how thin the wood is under the rod. Lesson here is there is no room for error or stress above the nut. Just thought I'd share the X-Ray with you. I think the pictures enlarge if you click on them.
Rod
"I Got A Banjo and I'm Not Afraid to Use it"