With all due respect David, I don't believe that A3 lock plate to be Spangler's work at all; I believe that work to be Kraus. I think I'm correct when I state that A.E. Kraus had already become head of the Hunter Arms engraving shop by the time the A3 Grade was introduced in 1895; and although there are some differences in the early A3 engraving patterns, the above lock plate is the later variation and would almost certainly be Kraus's work.
As to SAC engravers, I've found no evidence that SAC had an in-house engraving department; and have in fact, found very little information pertaining to SAC engravers at all. The only information I can recall at all is from the Steel Canvas book by Wilson in which he writes that SAC engraving was done by members of the Glahn family; and he shows a picture of a highly engraved SAC frame found in the surviving Glahn family records. He specifically names the family member thought to have done most of the engraving for SAC, and I can't recall from memory that individuals name; but Wilson also mentioned that this individual had engraved a SAC gun for Teddy Roosevelt (I'd sure like to see that piece!).
From my research, I believe that SAC subbed-out their engraving jobs; and the company apparently delivered batches of frames to the engraver with grade/coverage instructions, as engraved examples are often found in serial number blocks (and I've found several examples of consecutively numbered high grades). The most variation I've seen as regards engraving coverage in SAC guns has been with the early HOLLENBECK marked SAC guns with a Grade D frame stamp; and the most striking examples were consecutively numbered. One gun remains the most highly engraved SAC gun I've ever seen, and which was featured in a DGJ article some years ago; while the other D Grade stamped example had very little more engraving (line and scroll) than an early Grade 1, and remains the only Grade D SAC gun I've seen with no game scenes (other than an embellished Grade 3 that had been over-stamped "D").
