There are a ton of foundations, corporations and groups giving money, thousands of dollars in contributions, to the WT according to CitizenAudit.org documents.
Here's one example from the Edwin J. and Patti Curtze Foundation:
http://pdfs.citizenaudit.org/2016_10_PF/26-1439455_990PF_201512.pdf
In this instance they get dividends from investments and disburse thousands to the WT.
https://projects.propublica.org/nonprofits/organizations/261439455
The total extent of these foundations that are set up to get dividend income then turn over proceeds to the WT likely is an important source of revenue for the WT. Definitely much more than Sophia's ice cream money, or Granny Pioneer's $20 bill every meeting.
I would think that tracing the source of income from these foundations and large charitable donations not by individuals so much as by foundations and other paper entities may be one way to follow the money all the way to the Boys in Pennsylvania's coffers.
What's your opinion?