Hi Paulie,
Firstly, Sorry but I didn't address your issue on the muffler in your previous post.
Honestly I've never had any sort of issue removing these and as such have never cracked an engine block in the process.
How I do it is to simply use a long series pin punch (8 to 10mm) and place it against one of the teeth of the lock ring and give it a sharp blow and it generally comes undone on the first strike. Giving it an overnight soaking of penetrene etc. is a good practice.
Now that you've put up a full series of photos we can see that this chassis has either suffered from a catastrophic rail failure due to a non maintained clutch half which incidentally has already been replaced or it was well on the way and someone has simply tacked on some strengthening steel so that it doesn't get any worse, regardless it's currently looking rather ugly and will require someone with good skills to unpick it all and restore it back to original appearance with no scars left behind as evidence, also keeping in mind that all this will cost a fair bit over and beyond a normal restoration if employing someone to do this procedure.
Alternatively you could just tidy it up mechanically and just keep using it, they don't all have to be spotless show-pieces I guess and as such keep a look out for another that has a much better chassis to do a full resto on.
Cheers,
BB.
