Just a thought but ......
As the PCCC is in fledgling form and not taking money off of members at the moment then they are, surely, a private group of people who wish to place themselves in the position of offering rational representation to thos who wish it.
As they have, in effect, no income the they don't have to produce figures, say where monies originated or produce any other paperwork.
When they start to represent employees as a recognised negotiating body within BA and start taking subs then they will be required to keep accounts. Until then they have no such requirement and can release information as and when they wish.
Just a thought.