I've been reading the Anderson book. I'm waiting for the rifle to arrive to compare the barrel length and weight of the rifle to his description.

Anderson's account of the sight situation is also incompatible with the Gun Broker rifle. O'Connor's Minar-Sukalle had:

"claw mounts with a German Girard scope and a Lyman 1A peep on the cocking piece and a ramp-mounted gold-bead front sight."

This one has, of those, only a ramp-mounted gold-bead front sight.

Sukalle, Anderson says, replaced the barrel once, and (cheery thought) in "The Rifle Book," p. 217, O'Connor says he got rid of the rifle because 139 gr. loads were wearing out the barrel's throat.