Here's a thought for you.
In fine woodworking we use a "Japanese pull saw" to make very fine cuts the blades from 7" to 15", 7 tpi to24 tpi very flexible, long and extremely sharp with no kerf. They can be found online or at a local Home Depot or Lowe's.
You might be able to very carefully cut the glue lines then level you stab before re-gluing.