Note how the patch "feathers" out at the edges. It's crucial that the reinforcement taper off to nothing at the edges so it won't propagate new cracks in the top as a result of string tension.
Time to fit up a new end block:
Things are really getting along now:
End block clamped in place.
Here's a real forest of little clamps as I hustle to get the back glued up:
You have to work fast to clamp up the hot hide glue before it cools and starts to gel!
A light "scuff sanding" with 320 grit and I'll start to do a little French polishing to restore the finish:
This step wouldn't have been strictly necessary, but it does offer me the chance to hide the cracks that extended out beyond the tailpiece.
Now it looks great, and will be strong enough to stand the strain of being a mandolin again:
The shine will dull back a little as the crazing of the original finish starts to show through. In a year or so, it will be hard to tell any finish work had been done.