I doubt you'll find anything exact - I looked for am upcoming project with the same task. We've decided on a SEL-751, with SEL adaptor plates. The other thing to consider is that the Circuit Shield was a draw out relay. Remove the relay and use standard leads to test. If you are changing to any kind of newer relay, it really should have a FT or similar test switch. That becomes the justification to cut a big hole and use a SEL 700 series adaptor plate with FT switch in the plate. The plates are about $40.
You may also consider ordering a new door for the switchgear. Have everything installed, set & tested on the door prior to the outage. 15-20 wires to connect during the outage + testing AC & I/O circuits. The doors are not as expensive as you may think. If you have a switchgear / panel builder in the area, have them come out and take measurements.
