This is all news to me, I thought "Maxi" is just a brand name for one type of spring brake and has become generic like "Scotch tape"??
As Joe says, the new can is so cheap it makes no sense to try a dangerous repair that might still leak or have another worn out part fail later.
When I was looking for spring brakes for my n'04 it was hard to find them with the necessary front end on them. Not only is the push rod longer than most, but there is a built up area on the front of the can to clear the mounting bracket layout (stock bracket) I looked around for cans like these, found some at +$100 each, without the spring brake. part. So I just used my old can with a new diaphragm and attached some decent looking spring brakes that were available. Come to think of it I guess I jsut changed the service brake dia., not the spring part, as the new spring brakes did not need messing with.