In my opinion - a bad idea - transfers load to parts of the shell NOT designed to cope with it. The Dolomite was designed just as people became aware of the idea of crash protection, manufacturing parts of the shell to take specific loadings in the event of an accident. Modify this (by seam welding) and you can get all kinds of unknown stresses and loadings.
Best idea is to fit a suspension turret brace and maybe reinforce a few certain other choice points, should see you good
You really shouldn't have that much problem with the shell, unless you're putting obscene torque through it (as Darren will testify!)