I was thinking Hyak too, so much that I sent the link over to Brian to see if he remembered it. He said that it wasn't of his hand, but he thinks it looks a little Irwin-esque. In fact, I have this image of a guitar attributed to Irwin filed away in my archives that has a circle inlay on the peghead:
The neck is a little BecVar in its proportions, but Bruce made things a little more refined usually.
It's a mystery in everything except the year - if the builders are any relation to Alembic than it has to be after 1972. Just sayin'