You haven't posted anything that wasn't posted before, Coz. I have seen both ways online, both here and elsewhere; 72-01, and 72-001. FWIW, Rick Turner referred to it with the 001. He added in the same discussion that it was conceived and mostly constructed at the 360 Judah St. location in '71, and finally completed at the Cotati Chicken Ranch shop. I've never seen the end of the headstock pictured, so I don't know. It was the first one, so technically no serializing pattern was established yet. In interviews Jack said it took about a year and a half to finish, and that it was meant to be an experimental platform.
So no help. I was just throwing that out there for discussion. Hey, there's four 0's in front of #8... 🤣
I think we have more fascination with these things than the folks at Alembic themselves do. I've been trying to track down some of our own early numbers for Dad. He can't remember who got what, and I didn't often know who we were working for... I just did what he needed. Basically everything before our 8th banjo is a mystery. The first two are nearly identical, and he knows the two people who got them, but he can't remember who got which one... and it's been 43 years.