Except for poor Swiss like gilding and two important features, this 11J undersprung movement with hidden stud, applied index and steel balance would be an excellent example of a private label P.S. Bartlett (PSB), circa 1859. The top plate and pillar plate measure 42.7mm and 45.7mm, respectively, as the standard Model 57. The top plate encircles the barrel as on early Model 57s. The position of all arbor holes measure exactly with standard Model 57; the dial from AT&Co S/N 27902 fits as do other factory dials. The applied index and barrel bridge measure the same as on PSB #17053. The winding arbor and guard cup are identical to the parts of PSB 17053. The train looks standard Model 57 with 3-arm blunt-end escape wheel and enclosed English style pallet. The cantilevered potance looks like the standard part (the early part #215). A subassembly number 32 is stamped on the pillar plate and under the top plate in the same manner as on standard Model 57 movements; this along with the Russell number 21147. The number 32 is also stamped under the balance bridge along with 247.
Some minor differences: The regulator is similar, but the pointer end is a tad shorter than typical; although author has seen many differences among regulators, especially on early Model 57s. As reported with James Russell #20145, the balance bridge is a little longer (but not wider), the long pillar plate bridge is a little wider, and the oblong ratchet bridge is a little wider. It might be a coincidence, but the author has noticed that balance bridges are (typically ?) a little longer on Home grade movements (more metal on arbor end) and one Home bridge that was measured compares with this Russell. The differences with the long and ratchet bridges are quite small; perhaps the parts are correct, just out of acceptable factory tolerance. [Ratio of edges are measured so that they can be compared with photographs; e.g., width/length of the Russell ratchet bridge is 0.621, a little wider than PSB 17053's bridge with ratio 0.576; 7% difference.]
The two major differences: There are no peep holes on the pillar plate with which to view the escapment in motion! This feature was introduced by the Boston Watch Company, so how could this be a Waltham part? This Russell has 11 jewels, but the top plate jewels are 2mm garnet jewels burnished into the plate like on William Ellery grade Model 57 movements circa 1871-1872, a decade after the hidden stud PSB! The mystery continues.