Thank you huskybob. That is probably the same as the 660 plate. I am missing the deflector cup and the vent.
Can you measure the stud total length and the length of threaded part of the stud? Someone used carriage bolts as studs on my pump plate. It works, but looks bad.
Your photo also confirms the center support bracket for the junction box. I wasn't sure if that was original on my pump plate.