I thought this was an entertaining video, maybe more for amateurs like me to watch, maybe boring to the professionals on here, don't know -- but sharing because this luthier documents what he does well IMO.
It's a long video (21 minutes) so you can skip to 6:45 where the back comes off to see the old "repairs" someone had made in the past
https://www.youtube.com/watch?v=D7daGYXk6Fo
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