Having been around upright basses for the last couple of years, I realized many have repairs for cracks/breaks far worse than that.Fantastic! Just might become your fav Thunderbird.
I have a similar stress crack on my burst. It's more than in the finish, but is just fine. As long as the strings are on it's held nice and tight. Even off, it doesn't open up unless pressed. For the heck of it I tried getting a little glue in one day, but the crack is so tiny even under stress I'm not sure I did. I have no worries. Got mine (the burst) at a crazy low price and if the neck gives up, I've got some killer PUs for the Gibson!
The pick looks horrible zoomed in so much, but if you don't think about it you don't notice it when playing. I since smoothed it out a little.
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If it moves, you can get glue in there. I would go with thinned hot hide glue myself. I’m pretty sure there’s a good tutorial on the Stewmac site.




