Hmm.
The problem with this gasket is it is only for this application...
Not a bunch of options here...
On the RX forum, here is what they are doing for the same problem.
"Use annealed copper. #1, buy a sheet of copper, approx 0.03" thick or slightly thicker. #2 Take a propane torch, heat it up till its almost red, let it slowly cool. It should be annealed (becomes soft). #3 Stamp, cut any gasket you want (intake, exhaust etc). If it cools too quick (by dumping it in water and or cool oil) it will HARDEN and be brittle"
Apparently this is working well for them as their exhaust gasket is close to 100usd...
Hope this helps.