I think there is a miscommunication here. The hinge pins are on the back edge of the opening for the machine in the cabinet. The sewing machine is held in place on those pins by little tiny set screws in the sewing machine. If those set screws are missing, the machine will not stay on the pins.
I once bought a 301 in a nice cabinet for $50.00 because it was missing a set screw. I didn't realize the problem until I got the machine home. They had taken wire and tried to wire the machine to the hinge pin.
bkay