I personally wouldnt put anything metal in there. That just makes it more stiff on the mounts, and will make break it at the point on your next crash (we all know it happens.. esp starting out

)
So.. that said. How do you fix it. Get you some glass fibre kit.. any auto store should have it.. epoxy some fibreglass layers on there, and redrill the hole where you want it to be making it even more easier on you to mount the canopy and will get rid of the OVAL-ing thing.. I know what you are talking about, the battery stretched the canopy upfront and it makes the canopy holes elongate..
Or even easier.. get you some thick CA. fill the hole with that as much as you can, (where the elongation is) and let it dry out, and then just re make that hole there where the rubber grommet sits.
I havent used somethign like that before. It might help.. but if you loose one, you'll have to order them again, and wait.. while align rubber grommets can be found anywhere.. any LHS.. so its your choice
