Hey 82 daytona, that damage does not look real bad to me, I think (without seeing it up close) I would go ahead with the rebuild and splice in a section of the stringer, dig into the parque balsa and just finish it up, the stringer does not look to me to have been super high quality materials to start with (hard to tell from just a picture), if epoxy resins are used the bond that can be obtained is incredibly strong, if there are any doubts, my buddy just replced a major section of a delaminated bottom on his flatbottom and recently ran 118 MPH without issue, he vacuum bagged the bottom and used epoxy resins designed for lamination, much stronger than polyester resins.
If your engine mounts are rail type, the torque goes through the entire length of the rails, if not I would go that way, seems cheaper than starting over and I think in the end you will have a better boat...Again, may be completely full of shit, right to the top....
GT