Funny, I've been thinking about doing the same thing with mine.

You'll find that once you get the drivers out there's a fair bit of room to work in.

I had all the drivers out when I first got mine & I put a bead of clear silicone around all the joins. Don't know if it made any difference, but at least I know that now there aren't any leaks. Also put a new sealing gasket around the horn before I installed it. Picked up some Raven door & window seal that was perfect for the job.

I was thinking of putting some diagonal bracing (2 x 1) just glued & screwed across the back panel & the 2 sides. I suppose a front to back dowel wouldn't hurt either.

While you have everything apart you should consider replacing the caps in the crossover & doing the ground by pass.

Cheers,
John