Hi, just a heads up for people with pin holes or gaps in the welds on their collector or 2 into 1 pressings, you can mig these with ordinary wire . It's common practice in the trade to weld aluminised steel and/or stainless that way. All the systems are made to a price, (exotic materials obviously bump the price up) if it's a quick fix to pass an mot or repair a crack, anyone who can use a mig could help you. Ok, it'll go rusty after a while but it'll take a long time to rust through.
Just my thoughts on it really but if it's your pride and joy I wouldn't blame you for getting it done properly.