Hi Chris,
Soursop is a fairly common backyard tree in Eastafrica and I have seen many trees and fruits, but none as prolific as this. The fruits are not as large as produced by several other trees I have encountered here, but with less fibers as well which surely makes it a fine selection from the collector in Arusha. It is always loaded with flowers or/and fruits.
I don't sell seeds, but would be happy to trade for other species; wrote you a message.