xj downpipe to cat leak

Hey guys.
So Ive been battling with this for years. My frontpipe/downpipe where it connects to the cat. leaks.
I have the paper/metal square gasket that i have replaced over and over now they only seem to keep it sealed for a few months.
Does anyone else have a good fix for this aside from welding it?

The union is probably slightly misaligned for some reason.

I'd try cutting my own gasket(s) out of thin steel or copper, using the
original gasket as a template. Two or three layers of cut-out gasket
should do the trick. A roll of roof flashing material from the big box
store would be a good source for the metal.