[Rich]

I'm of the opposite opinion. I believe 99% of the time it's the wood. There's no reason the paint would crack in a specific spot unless the wood cracked underneath, and I don't believe you'll ever see a hairline crack in anything when you sand it down.

Basswood has very straight grain, soft, and extremely low resin, and very prone to cracking for those reasons. Though we've all seen cracks on alder and mahogany, I don't believe any wood is immune. In the end, it's a common occurance and virtually expected especially on older guitars. IMO it's mostly shock related, from shipping, dropping a case, etc.

 

[Rich]

I've had them in mahogany against the gain, when I said 99% of the time, I'm talking about basswood, but any wood is prone to finish cracking in that spot, I believe in basswood it's in the wood. In my position I'd rather state a worst case scenario than the hopeful.

 

[Rich]

I mean, if we are splitting hairs. (haha) the only way to REALLY know would be to remove the paint and check under that, not just the inside of the neck joint... a hairline crack doesn't always have to show all the way through to the other side such as seen in Greenstick and linear fractures, not every crack has to be what we usually imagine such as those compound, compression or transverse in nature.
but no one is stripping paint off a guitar before they buy it. so.
I'm also kinda spitballing. knowledgeable-ish, but terribly inexperienced and unprofessional over here.

I don't believe you would see the hairline crack after you stripped it. It's not like the paint was wet and seeped into the crack when it cracked to make it show when you strip the finish off.

 

[Rich]

An 88' FP with a neck pocket crack may get a small discount over one without, considering 2 guitars in the exact same condition otherwise. But nobody is not buying an 88' FP because it has a crack. They're literally expected on old basswood guitars and just a bonus if they're not.

 

[Rich]

Tell Steve that EVO's isn't structural. But it's been beaten to death on tour for near 30 years. If it's in the wood it's structural, but 90% of the time it cracks, and never changes. But I've had JS's with a crack all the way down the back past the trem cover.

 

[Rich]

Its actually strange, now that you mention this. In person, I see absolutely NOTHING. After posting the image and scrolling through and seeing where the crack "Was" and where its at now, it almost looks like a witness line??? Like theres nothing there, Im sitting here with it in my hands and I dont see a damn thing lol, but in that photo theres "something" going on.

The picture is 5x life size. Try looking at it with a 30x loupe, I have to use one to diagnose alot of finish issues on new guitars.