I ordered a new converter from www.thefamousfour.co.uk this also came with two new gaskets. I picked up some galvanised steel nuts and bolts from a local store assuming the old ones would need grinding of.
The old converter still looked pretty good, the bolts on the back part where also in good enough shape to be removed with using a spanner. The cat and exhaust have a-symmetrical mounting points, because of this you can only mount it on in one way, not one of the wrong ones, brilliant!
New cat, new gaskets, new bolts looks good! I expected it to go all wrong, but no leaks or problems, it also didn't fall of!