Lazy Daze Owners' Group

Well, do you want to do it right or just get it weathertight, doing what you can to repair some of the damage without complete disassembly, hoping it holds together for the duration?  It's 32 years old, how much are you willing to put into it?

If LD repaired it, at a minimum, the lower aluminum panel would come off to access the damage. Pricey.
LD doesn't work on models more than 20-25 years old anymore, so you would need to find a shop that could do it or make it an involved DIY project.
Without an inspection, any suggestion is a wild guess.
I would start by pulling the complete heater out to get a good idea of what is damaged, repair as much damage as possible before reinstalling and sealing it.
You should be able to partially access the rear of the heater from the interior, to get a better look without removal.
The wave in the side may indicate more extensive damage.
LDs are much stronger than most RV, many older LDs have extensive rot damage, yet keep rolling along with the remaining intact structure picking up the load.
Pull the water heater out and see what's what. Post some photos too