You can install an inspection port near the tube and do glass work on the inside through that. Not hard work.
What Matt means is that it is not that hard if you're a contortionist and have really tiny hands
Actually, I posted some real detail on this process in the H17 forum, boiled down to this:
I repaired one and then beefed up the ones that are NOT broken so that they would not break later.
I put three hose clamps around the tubes, one in the middle, the other two are about 3 inches from top and bottom. I figured these would provide real structural strength.
I epoxyed 3 layers with glass cloth OVER the hose clamps.
IMPORTANT: after you cut the holes for the inspection ports, do NOT install the bezel until you are done fiberglassing. The extra 1/2 inch diameter on the hole makes a big difference in how much you can do.
Again - look around for other posts by me and you will find everything you wanted to know - and some stuff you didn't want to know too