I also build rods, great work on preserving the underwrap, trim tabs look great.Here is a rod repair that I did for a guy. The rod is a Calstar and their underwrap is a proprietary turquoise thread that isn't available to the public. Here is the broken guide:
Replacing the guide was no problem, I had a box of matching guides and if Ib could have striped to the blank and retied. a new guide it would have been 45 minutes plus finish work tops but I knew I couldn't match the under wrap. I had to try to preserve it. I used a dental pick to raise the thread and unwrap it from under the finish:
One side then the other:
Until I had removed all the old overwrap, broken guide and enough of the old finish to provide a solid bed for the new guide:
Then it was simply a matter of seating and wrapping the new guide, match the gold decorative trim and finish:
For comparison, here is the adjacent guide in original condition.