Chassis Rot + Diff Question

["Iain Wilson" <iain.wilson2@virgin.net>]

When I was rolling around on the garage floor under and around Holly (my
Mk3) I noticed that the inside face of the box section rear chassis turret
(the bit the damper is bolted into) is very rotten indeed - I reckon I could
have poked my finger through it if I was brave enough.

Is this part of the chassis highly stressed? could I get a plate welded into
that section or am I looking at a new chassis?

Regards

Iain & Holly (& Jan - it is Valentines Day after all)