I feel for you, I have worked out in all weathers for a large amount of my working life and now long retired, I am glad to be able to get indoors if weather bad, it's no fun as you get older, memories of fitting a gearbox on broken down Ford Transit twin wheel scaffolding lorry at the side of a steep hill with the heavy rain running down all over me and through my overalls on my own, still linger on.
I see what you mean about the three bolt flange, it doesn't really allow exhaust much movement even with that spherical asbestos type gasket.
With it not having the later two bolt system with the spherical bolt ends allowing more movement and the stops on the spring compression must make it quite rigid.
Is your exhaust system a full length exiting at rear of vehicle, some of mine were much shorter and did an L shape turn exiting just behind the driver side door.
Although I am not sure how regulations etc. would be for that especially if traveling abroad. Most of my vehicles were work type vans or pick ups, so side exiting exhausts were less important re exhaust fumes, although I never had an issue with them and often drove with the window down.
By the way looking at some of your mounting brackets, do yours use rubber and canvas straps being of older design?
The later idea of exhaust hanging from rubber rings does seem to give a more flexible system better allowing for engine movement.
Another long term modification would if possible, be to fit the later exhaust manifold and front pipe with the two bolt flange and spherical bolt arrangement.
To see if even viable it may be possible to see if the exhaust manifold spacing is the same as the later engines, on the 8140. series I have a feeling they are, but not sure about the 8144.67 that you have.
You would have to go for a non turbo version, but at least that is easier to fit in some ways.
Apart from that the only thing you can do is make sure with your three nut arrangement that the springs are not too compressed, so only just keeping the gasket gas tight whilst still allowing movement to take the strain off the exhaust system.
Perhaps
@Communicator can give further thoughts?
