I am concerned about the accuracy of some numbers at BOINCStats. WCG, which in the old build showed an over all totla of somewhere north of 2 million, now on the new build is under 400,000?

north of 2 million??

WCG itself reports 603,804 members -> BOINC and old UD together.
Thousands of old UD-members stopped before BOINC was introduced and thousands of old UD-members never made the switch to BOINC.

Conclusion: 603,804 minus 392,515 = 211,289 UD-clients never made the switch to BOINC or stopped UD-crunching long before.

WCG never converted the old UD data to BOINC. That action is on their ToDo-list for years now and will probably never happen.