I am Treasurer for a music charity (The Sheffield Chamber Orchestra:
www.sheffield-chamber-orchestra.org.uk) and we do indeed receive a substantial chunk of our income (nearly £1000 in recent years) from Inland Revenue Gift Aid refunds on members' subscriptions and donations. But we have considerable income and expenditure - our annual turnover is in the order of £17k - £20k; that's what it costs to run a small amateur orchestra giving three public concerts each year.
The Charity Commission requirements include an establishing an executive committee of Chairman, Secretary and Treasurer as a minimum, who are also Trustees of the organisation concerned. We are required to keep proper accounts, audited and examined by an independent person, hold minuted Annual General and other Meetings, etc; all the stuff that Societies and Associations have to do, so there is quite a bit of admin work involved.
I'm not at all sure this is appropriate for this forum, at least as long as it remains a forum. If one was thinking of setting up a charitable organisation or society (such as the International Concertina Association, or the several UK Accordion Clubs) which held meetings and events for its membership, then that would be a different matter. If we wanted to form such an association, then this website and forum could be affiliated to it, I guess, if Theo felt like it.
We do have the potential membership for such an organisation, and it could be really good. But it would need some dedication and hard work to get it started and more importantly, to sustain it. Happy to advise and to be a member, but helping to run the Sheffield Chamber Orchestra is plenty for me to be going on with, so count me out from an executive or other committee capacity.
To return to the current situation, I know that Theo receives cash donations from time to time which help defray the costs of running this website and forum, and I believe he is generally happy with the way things stand at present (correct me if I'm wrong Theo!). I also guess that if increased capacity were required (as seems likely), the extra costs could almost certainly be met in much the same way.
I would like to reiterate once more my thanks and appreciation to Theo for running and maintaining this website and forum. I love this place and everyone on it (even if I get grumpy from time to time

); it enhances my life.