Thanks for the information Barbara!
I've not looked at the figures closely enough but the IBSA accounts show voluntary income of around 32m, 10m (!) up on last year. I don't know if any of this incorporates funds from other countries either directly or via one of the other UK WTS entities but that's an extraordinary amount of money per capita.
I would imagine that a large amount of this is due to the money grab from the halls where they have had bulk transfers of cash stashed in congregation accounts as well as substantial monthly donations from each congregation. If this is the case then I would suggest that their strategy is to replace the income from literature with the back door rent on the halls.
I also suspect that expert analysis will reveal they are moving the money around to avoid it being somewhere where it could be extracted through litigation and/or a change in their tax status.