Here's the lawyer's address for anyone who would feel more comfortable about sending donations this way instead of to a PO Box:
http://www.jehovahs-witness.com/forum/thread.asp?id=24240&site=3
SHUNNED FATHER
c/o Mr. Robert Calvert
McCarthy & Tetrault
3300, 421-7 Ave SW
Calgary, Alberta T2P 4K9
Canada
Love, Scully