It's a modified industrial
These are just modified Juki industrial machines. Very heavy duty and basic. The feed dogs were removed and handles added. It was sunk into a carriage base so as to move on a frame. The foot controller was swapped out for a control unit nearer to the handles.
Since these are from the 90s or so by now the wiring likely needs to be replaced and this is best left to people who know what they are doing.