I must concur -- this thread is a bit confusing to those just interested in the conclusions, not the data collection. I'm going to suggest that anyone who has "number crunching" data just send me a PM, and I'll share it with Lee Enfield and Seaforth72, who are also collecting data.
Bottom Line: we are getting closer to the answers.
This is quite disconcerting and probably explains why we have so many anomalies in outside the typical block ranges. We should probably post a warning to any buyer that anything outside verified block ranges be very carefully inspected to be sure its authentic. The block ranges that seem secure to me are: 1944-45 -- 68L 320 - 68L 400, 71L 000 - 71L 651, 74L 001 -74L 350, 80L 8001- 80L L8099, and 90L8000 - 90L8360. There are many authentic ones in the 1941-43 range, but they don't seem to have "block serial numbers" (small batch lots instead).
In thread https://www.milsurps.com/showthread.php?t=55722&page=5 Hal O'Peridol give us another clue to the Missing Wartime Snipers:
This would lead us to the conclusion that many Snipers were simply scrapped for parts after the war as surplus. While the Numrich parts may have come from more that just Long Branch Snipers, it's important data. Thanks Hal for the clue.