I've just replied to you on Twitter about this, but I'm afraid you can't sell T-shirts (or anything else) using our trademark. We need to reserve the right to do that for the foundation; it's the way we intend to support the charity and a way we raise money outside donations.
The shop will be setting up again mid-month, when we have an employee to manage it (it's a full-time job and I don't have enough hours in the day alongside everything else to run it).
Thread closed, but please email me if you need more clarification.
Director of Communications, Raspberry Pi