SG-688's stocks in Post #25 show epoxy or similar in strategic places inside, similar to mine, and his stocks are described as "in the style of Joe Blackford but were made by Art Kanthack, an LAPD officer who made just a few grips".
Post #41 by offrdmania has the birdseye maple set identified as by Stark, with the screw head on the right side, unlike mine or most others I've seen here. So maybe that is a feature exclusive to Stark. This screw orientation is also present in mikepriwers Post #8, identified as by Stark.
DCWilson in post #58 said "We occasionally see inset ebony plugs over the receiving grip screw escutcheon on some products of the LAPD grip makers. It is my perception that Blackford stocks always have an ebony plug. I have long suspected that he used this design feature as a signature". Blackford = black plug, if so a clever personalization by him.
Vtgw938 in Post #62 has checkering that doesn't quite fill the entire contour, like its missing the very short last line near the upper finger groove, just like mine. These are said to be by Blackford. See this also seen in Post #31 by LazyH, also said to be Blackford.
Conclusion? My brain hurts lol. Really, I'm thinking my stocks may be misidentified as by Stark when they seem to be more like Blackford or Kanthack. Mine came to the previous owner already marked as being by Stark but it's printed, not autographed. Perhaps written by someone without access to all of this info who went by the data available at the time, word of mouth, opinions, who knows?
Great Forum full of knowledgeable members, thanks to all for sharing and please keep it coming.
Todd