iirc, the Estes 4" tubing used in the MDRM is the same as Loc 3.9 airframe. If I am wrong on this someone please correct me.It's a cheap enough part on a nice enough rocket I'd just order another; or at least do something to strengthen it, else the first heavy landing might go poorly.
http://www.rocketryforum.com/showthread.php?136670-Mega-Red-Max-Tube-OK&p=1627280#post1627280Be willing to bet Estes makes it right and ships you new tubes .
Just my experience. Fix the other stuff and use it elsewhere for one of those, always wanted to try that projects - if it goes wrong, no harm done.