There are lots of good arguments for replacing the seats in a TR6 with those from a Mazda Miata or similar more modern design. New foam and covers are expensive, and upholstery is difficult to get perfect. But the seats in a '69 are unique, the only year they were used, so i thought it was worth trying to rebuild mine rather than replace.
Notes and lessons learned getting a 1969 Triumph TR6 back on the road.
The engine on the TR6 was unusually noisy, especially on acceleration, with sort of a slapping popping noise in time with the speed. I eventually figure out it was a bad exhaust manifold gasket, and now i can pick it out from a mile away - it seems to be especially common on Ford trucks and SUVs.
I've done a fair amount of other cleaning work around the engine, but had never really dismantled the top end past the carbs, when we rebuilt them. Everything was pretty crusty under there.
The TR6 has the original steering wheel, again a unique part of the 1969 model year. It is (i think) the only year of TR6 that had holes in the spokes. Starting in 1970 the spokes had slots instead, which are apparently less likely to trap your fingers while you're driving.
It's a 15" wheel and thin, which is in keeping for the time, but often replaced with a smaller diameter, thicker wheel more like modern wheels. I admit that an extra inch or two of leg room under the wheel would be welcome, i like the original too much to replace it.