I hate to complicate matters, but it sounds like you might have something other than a carb problem. In my experience the cars aren't that sensitive to carb mixture adjustments, they will run with mixture off, just not as well.
Guy from the club brought his TR6 to my house to look at the rear suspension on a lift. Car died as he pulled up. We messed with a lot of stuff. Turned out to be the new rotor that was put on as part of a recent tune up. Not saying it is your rotor, just new or replaced doesn't necessarily mean good.