Looking at 410.3875 down here now and the signal strength is twice what it's been as recently as this past Monday, although DSD+ is still reporting S2-1.2 DCC:1 so presumably still coming from the same location. I'll let it run tomorrow and see what if anything turns up as new data.
Typically I see registration requests for 830001 to 830011.
I'm seeing the Group calls coming from 999901 and 99902 (same as your activity). I suspect these are probably base stations since the calls are OVCM which I believe is an All Call type thing.
410.3875 CC signal level is now a solid 50dB over the noise floor here, a considerable increase from just 3 weeks ago and easily 40db stronger than when I first reported seeing it active in December. I'd surmise that means sites are coming online fairly regularly now.
It looks like the Tier 3 is starting to come alive slowly. There been a bit of activity on this system from last night/this morning on the Edgar Site. I am not sure if its testing or what but I see TG's 201 to 208, 210 and 1677215 all with a few hits with RID's in the 8XXXXX range and 9XXXXX range.