Since they just wanted to add some new features on top and present a better rack-based interface to the user, they decided to build a bigger box, put one of the old devices inside the box, then put a modern PC in there, and just link the two devices together with ethernet through an internal hub also connected to the backpanel port and call it a day.
The problem is, if you do an update, you need both the "front end" and the "back end" to coordinate their reboot. The vendor decided to fix this by adding a simple URL to the "backend" named: /backdoor/<product>Reboot?UUID=<fixed uuid>
Their sales team was not happy when I showed them an automated tool in a few lines of ruby that scans the network for backend devices and then just constantly reboots them.
They still sell this product today. We did not buy one.