So in the off season I will be lining my masonry chimney, it is a 7" square id flue and it is not straight, there is an offset in it 3 tiles down from the top. So in order to be able to run an insulated liner I am going to go with 5.5 instead of 6. My question is where can I get a 5.5 brush? I looked at chimney liner depot because that's where I'm gonna get the liner from and they only had 5 and 6.I once trimmed down a 6" brush to fit a 5" pipe and it isn't an experience that I care to repeat.