Fender 74 Jazz bass neck with 8 holes.

Could it have been a Fender screw up? The upper set of four look like they have never had a screw in them.

 

No way of guessing w/o more pics.

 

It’s common in this era. I’ve seen dozens of them like this, sometimes with only 2 extra holes, sometimes with 4. If you look closely, the extra holes probably aren’t even threaded, just pilot holes. Seems Fender had a loose jig at this time and messed up the hole placement when the necks were being built, so they re-drilled them during actual assembly. Too bad you canceled the transaction over it before researching/asking, it’s legit.

 

Confirmation of what people thought of CBS Fender in the 70s

 

Fender necks don't always match up with a MIA , MIJ or MIM , someone had that on another body at some point . That smaller hole is factory , they drill those for handling during the finishing .

 

Just to show some evidence of what I know from years of collecting vintage Fenders, here are a few shots of some vintage Jazz necks with this anomaly. I personally took every one of these pics. They are ALL pearl block Jazz necks from late 1973/74 (I’ve also seen these extra factory holes as late as even 1978, but ‘74 seems to be the most common by far). I also don’t recall ever seeing them on a P bass neck, only Jazzes. And notice how on one of the photos (2nd to last), you can even see the extra holes were never threaded, just drilled...

 

That's exactly what I thought too. In fact I posted that right after the OP posted the thread, think I was the 1st reply.