Steve Darnell who leads my water sampling team for the acid water samples is going to teach a rod building class in the next few months. I'm sure you could just build the one segment instead or a whole rod, or you may want to build a whole rod plus fix your segment
Steve has been meeting with several people including myself teaching fly tying over the past year, and really knows what he is doing. A lot of rod building from what he said comes down to having the right jigs, etc.
It will be free in West Knoxville most likely at Faith Lutheran Church for you or anyone else who is interested to join in. No religious overtones or anything like that just some avid fly fisherman trying to learn something