Food for thought on this unique rifle:
The mainspring is its own part. The trigger guard is not the mainspring.
Touch hole picks and feather holes are normally flintlock associated.
Image 33 in the link clearly shows stock cut-outs for a flint cock shoulder to arrest on the top of the lock plate and a divot farther back for full cock clearance for a long flintlock type cock throw.
The upper leg of the main spring looks like a frizzen spring combined with the main spring.
There appears to be a filled lock hole just above the upper leg of the main/frizzen spring.
The other example of Glaze’s work in the link is converted from flintlock.
The Golden Age look of the rifle makes sense for the Flintlock or early percussion periods.
Did this rifle start out as a flintlock?
Also, this lock mirrors the primitive Hmong “monkey guns” whose locks were hand forged using a similar basic mechanism, with much less sophistication. They were flintlocks.
Bill Paton