Right, basically, the way i see it, if the shell isn't rotten, and hasn't had shitloads of welding, and isn't rusting/going to need welding anytime soon then keep it.

You should never let go of a tidy shell.

As for the cosworth parts, it depends if you can relasitcally afford to have it painted etc. Plus theres the fact i personally don't like drilling holes in cars that aren't rusty, for obvious reasons

Looks good as it is to me