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I have a Gibson Chet Atkins in the shop with a nasty headstock re-break. The headstock was broken off previously and repaired (at another shop). The repair to the front of the headstock has held, but the main break opened back up along the same line. Since the headstock is hanging on by the headstock veneer I can't really open up the crack enough to clean out the old glue residue that's deep inside the break.

I'm looking for advise as to whether it be best to remove the headstock to prep the surfaces fully before regluing, or should I just clean out what I can reach before gluing this back together? I've had breaks like this before, but none that had the added complication of old glue residue. I've been using West Systems epoxy and adding splines on difficult breaks like this recently with good results.

Appreciate any help. Thanks.