Never throw old stuff away
We used to sell software with licences linked to the HW ID. We once got a support call from a customer who'd had a board replacement on some very old (but still supported) HW and needed a new licence key for an old application. The problem was that the entire team who had managed that licence software had been laid off years before, when we gave up on that model and stopped selling those products. Their systems were long scrapped.
Happily someone remembered that I had been doing the client-side work for many of the licensed products, and called me to see if I could help. To simplify the dev and test process I'd once persuaded the license centre guys to give me a bootleg copy of the tool to generate keys, after swearing cross-my-heart to only ever to use it for lab testing. Much excavating in decade-old email folders turned up the tool & the instructions, and a new permanent key was generated for that customer. In the years that followed we had a few other cases like that.
Never delete old tools, you just never know when they might be useful!