1. The old rig is a larger jib that sheets back on the tramp, a pinhead main and single trap. The new rig is a smaller self-tacking jib, a larger square head main, double trap with a spinnaker.
2. T-boat=10ft beam, road legal width=8.5ft. Depends on how many tickets you are willing to pay and how many mailboxes you want to take out.
3. I'm sure you could single hand it, but it depends on the wind strength.
4. The T is a very open design as far as the deck layout goes. They are as individual as the sailors on board. I doubt that you will find a page that lists line lengths. Imagine that you will have to strip 95% of the deck hardware off, relocate all of it with mostly new hardware. Given the age of the boat, I would suspect that all of the standing and running rigging will have to be replaced. I would think that you will spend more on rigging than you would on the boat. Rough estimate, 3k for sails (1000 for spi, 1200 for main, 4-500 for jib, 3-400 for battens). I couldn't comment on standing rigging, but I know Dynaform wire is more expensive than standard 1x19 wire. Couple of hundred bucks for a spi pole, ~260 for four spi blocks, ~350 for main blocks. Thats before you get all the little 10 dollar blocks for all the control lines. Then the lines themselves. Possibly/probably need a new tramp. What condition are the boards and rudders in? I think there is at least 200 dollars in just the self tacking track and 500 in the mid-pole (Guck) snuffer.
Does the mast have diamond wires on it? Who made it (mast and hulls)?
If you want to go handicap racing, the T is not a really good boat to do that with. Since so many great sailors sail that boat, the PN has been driven down to the point where you have to be as good as they are to sail the number. If you want to race one-design, a 1970's boat will not be competitive.
Not to sound so down on the idea, but it's a very involved process to convert a boat over. Knowing where to place blocks and why takes a lot of experience. I helped convert a T-boat last year and learned quite a bit in the process. I'd love to have a T, they sail so well, but the pains of owning one and being competitive. There are much less costly and demanding boats out there with great one design racing. I would also consider that there would be very little market for a 70's set of hulls with a new rig on it.
my 0.02
Will R
