to be honest i would've taken it off his hands if it were for free.
the labor you are about to invest is to restore the tank is time consuming. but the good thin it seems is its an older tank with thick glass. if it is at least 3/8" thick (or 1/2" even better) then i imo its worth salvaging.
theres another thread going on and i'm sure plenty others in forum detailing steps to re-seal a tank. but its basically the first step i took when i salvaged an old 75g that is now my cichlid tank.
so first priority is the re-seal and the frame uptop is no big deal to adheare back on once it is resealed. many people de-rim tanks to get a frameless edge, but for an old tank, i would put it back to add stability.
after resealing and restoring the frame and miscellanous cleaning... the next priority is a flood test.
flood the tank halfway first if you are not sure or flood it full if you are confident in your handy work. let it hold water for at least three days a week even better. carefully monitor for any kind of water. even the slightest evidence of moisture, i recommend draining an reseal the edge. its can be a process but rewarding as i was able to save my 75g.