Welcome to the HOC Max.
Nice score!!! That's a very interesting guitar you've picked up. Any shots of he headstock straight on and do you know for sure that a luthier "reshaped" the headstock? I'm not so sure, I think the guitar most likely received a new neck at some point.
or
I do know of a very few "open book" H150's out there from that era and I'm now wondering if that's one of them.