The reason the system "worked" was that at launch, the software application looks to see if the dongle is plugged in and if it finds that dongle and the licence key, it will run the software, it will allow the software to launch.
If you do not have the dongle plugged in, the software will not launch.
So, technically, you may have purchased the hardware, but (perhaps) the folks that sold this to you were not clear to you that they were not actually selling you the software - and while they may have included the computer with the software installed on it, but it will never work without the dongle.
So, yes, this is why "the previous owners kept the dongle something about Heidelberg using that dongle to run their new unit"
They may have purchased some new hardware, but did not need to buy the software they already owned (which requires a dongle to launch and run )
So, you have several choices - you can fire the person who did this deal because the did not ask enough questions, or - if that is you, you can sue the criminals that misled you and didn't explain that you bought something that needs a dongle to run it ( but didn't sell you that as part of the deal, basically selling you a boat anchor )...
Or - stop shopping for software. I would contact
Bret Farrah <
[email protected]> - they sell prepress software solutions, perhaps he has one for you that is less than 9k