Start with the MG Car Club in which there is the T Register.
http://www.tregister.org/And MGCC Germany.......
http://www.mgcc.de/I passed on a TC about 20 years ago. It had been under a tarpaulin for years, had a bent chassis and fibreglass wings and no instruments................But it was only £1,000.
I've ridden in three T types. The first was a '39 Tickford bodied TA, which was quite nice, but full of rattles. The second was a TD which I vetted for a buyer in Northern Ireland. I drove it round Rotherham on a cold and wet December night. The clutch was shocking, but otherwise it was a nice car and the buyer bought it after my appraisal!!!!
The third was/is a Black TC with green upholstery which belongs to a great friend of mine who lives in Wiltshire. It was bought by his father in law who courted his girlfriend in a TC in the late 40's. He wanted to recreate that TC, so paid for a no expenses spared rebuild. When he died, he left it to his daughter. The Triumph Gloria convertible restored for the same reason went to the other daughter, and both come together for family weddings. The first time I rode in this TC I wasn't impressed. It seemed sluggish and the chassis is definately the fifth spring. This car nearly took the end off two of my fingers. The fan is black and you can't see it turning.............. That hurt a lot.
But the second occasion was a blast over Salisbury Plain - keeping to the lanes, on a warm August evening with clear blue sky and not a breath of wind. It was fabulous. What a great car.