It has no strap button on the heel or bass side Mickey Mouse ear. No holes and mint, unbroken finish, so I conclude it never has. As Gibson had been putting strap buttons on for years by then, this reinforces my view that this is a unique early production batch.
I guess the idea would have been to attach a strap via a string through the space between the strings and the headstock behind the nut, like on a folk guitar.
I tried this. The balance is all wrong and anchoring the neck there means the guitar doesn’t move with as you move around the fretboard as I tend to do. A lot.
So I’m left with a quandary. Consign myself to playing it sitting down (ie very few gigs) or drill a hole (OUCH!)….