RP, for this particular excersize I highly recommend getting us some photos so everyone can see exactly what you are talking about. There are some very creative minds on this forum and a little visual would go a long way on this one. Can you help us out?
Edit: Taking a wild shot that you're talking about the blower housing. I am not sure the one you have but is it one of these?
Also, what if instead of reinforcing the housing directly you just add an aditional rub guard or wear strip that would take the obuse and would be replaceable? Maybe attached to some framework. Just noodling.