If you're willing to do a bit of DIY, plastic welding for structural strength isn't terribly hard. Getting it to look perfect is definitely tricky, but if you just want to stabilize and strengthen, you can definitely DIY it.
You can do some searches - a lot of motorcycle guys have howto's on the subject. If you really want to embrace the DIY look, check out zip tie stitching, and then get the sticker that @
Tcoat suggested.
I've done both plastic welding and zip tie stitching on MC's in the past, and had some pretty good results. I grabbed a couple of wrecked body parts from friends to practice on, which helped a lot. If you don't have any MC friends, you can probably pick up busted up plastics from eBay on the cheap.