I put this together a few years ago, it’s a jig I carried over from the guitar factory and modified it to work on a smaller scale. Basically it’s a mold that is fastened to a piece of MDF with enough space at the centerline for a .022 flush saw to be inserted and used to trim the ends.
Wedges hold the sides against the mold and there is a slot set on the centerline that accepts a Japanese flush cut saw. both sides are trimmed with the same cut so they fit really clean and neat.
The jig also doubles as a cooling jig after bending, again, the wedges hold the sides in place to the profile of the mold. See pics below
on another note, Rosanna is all blocked up, linings are bent and ready to go, next up sound hole and bracing the top and back. this one is going to be nice with a one piece back and top out of flame maple.