Old licences for suites and stand alones

I recently acquired a joblot of macs and Adobe mac software from a company who had closed down. These are older versions like creative suite 2 3 5 all with licence keys ( and there's some dinosaurs like photoshop 3..) 

Is there any way of checking if these keys are still active and is it legal to sell the software. I was assured the licences were no longer used as they purchased new versions every year or so.

Any advice appreciated.