For future reference, that part is called "oil filter housing". And it is a bit of a PITA to replace, because you have to remove timing belt cover to get to it. And at that point, it makes sense to replace your timing belt(s).
You are lucky to find someone to TIG weld it on the engine!
We actually took it off to get it welded.
Only had to remove the lower section of the timing belt cover.
And have just had the bottom end rebuilt so it seemed a pretty easy task compared to having to throw the engine back in, as we had been doing all weekend haha
Edited by Mitch B, 01 February 2012 - 10:02 AM.