To get back to the original question, it's dead simple. Look around other bike designs and you'll find push fit exhaust pipes are surprisingly common. They work well and require only fairly basic trade knowledge to fit.
I believe your Triumph had a crossover pipe close to the head as standard. If you then look at the exhaust system as a whole you'll see that if fitted as per factory with all the correct bracketry, the crossover pipe and Godwot it's just about impossible for the system to blow off. All you have to worry about is some possible leakage around the pipe up inside the exhaust port. It didn't leak when new but who knows what has been done to the beast in the 50 years since.
If there is some leakage this is easily addressed with a reasonably sized ball-pein hammer. One expands the pipe a whisker at the leakage point with the ball end of the hammer, usually just a few thou will do it and tries again. It gets easier with practice.
Nothing fancy is required, costs zero, just skill with a hammer.
Push in exhausts are effortless.
Cheers,