Nice work!
I made down and dirty alpaca halter for my sister in law using just glue and rivets. skived, lapped and glued the "joints". No stitching hence the down and dirty. real quick build once I got the pattern worked out from a nylon one. The angle of the nose/chin band is imprtant on these little fellas adnmesed with my head for while.....I am used to horse halters.
I used 3/4 strpa and hardware and they say they would prefer 5/16 next time.
It is doing good service as a general use halter. I am working with here to design a fancier show halter, perhaps with off colour stitching which looks great on yours.