New Hermes/GravoGraph machines generally had pretty decent hardware. Frankly, I'd remove whatever is necessary in order to first slide each axis thru its full travel, listening and feeling for the condition of the linear rails and bearings. If they turn out to be decent, I'd scrap everything but the motors and rewire it with a new control pushing brand new motor drivers. NOTHING they had for electronics is really worth saving. It was all proprietary, all completely lame by today's standards, and was about as ergonomic to use as, well, a vintage garbage CNC control. Things have changed so, so much !
Your options are to pick and choose individual components.... motor drivers, power supply, control software, or find someone with a "plug and play" package. The only really decent plug and play package I would recommend comes from Flashcut CNC. If you purchased a plug and play system from them with motors and all, you likely could have it converted in half a day, and, be running state of the art software to boot !