Haven't seen this one before:
https://www.vintageguitar.com/3665/gibson-es-300-prototype/?fbclid=IwAR3MsK17l9eGzr-1Yw2V9LImuX4Jax9SHOiFlcNVASxXc1Q2Xr-mTMCoBVM
(https://www.vintageguitar.com/wp-content/uploads/ES300_Web.jpg)
(https://www.vintageguitar.com/wp-content/uploads/LesPaul3_Web.jpg)
I hadn't heard of it either. Good article, and it shows that later innovations like humbuckers and split coils weren't new at all.
It's something else for sure. But the 300 with the long pickup was a regular production model I think, not just a prototype.
It's well documented in Gibson litterature even down to pickup design features.
But I can see why it didn't set the world on fire, pretty weird (but Gibson-ish in a cute way).
Thanks for sharing. I love old Gibson jazz boxes. I saw pics of this model but never really knew the story behind it.