So I took care of it. I match drilled and counter sunk the new angle.
The only thing I need to figure out is do I seal anything with firewall sealant. For example...Do I apply a layer of sealant between the firewall and angles to provide an extra layer of protection? Do I prime the angles? I tried to do some research and basically I figured out that its darn near impossible to get CS 1900 sealant in Canada. I think I may have to drive to the States to pick some up. Aircraft Spruce only sells the 3M fire Barrier 2000+ which is not as good as CS 1900, but given the circumstances. My choice is narrowed down to using a thin layer 3M fire barrier between the angles and the firewall. Guess I need to put in an order.