https://www.amazon.com/gp/product/B00002242B reviews are spot on, the installation is kinda "figure it out" but it's been nice to use. The center rings were very tight and hard to remove/insert but sanded down ok to fix that.
This plate looks very similar and is the first result for router table plate on Amazon.
Just got this finished up last night - looking forward to my next project where I'll need it!
I picked up a rock-solid custom router table off of CL back in December that looked similar to Norm Abram's Ultimate Router Table design. The door was off and missing a hinge, a drawer was missing, and even though it looked to have been pre-routed for a plate, the router plate insert was missing.
After taking some careful measurements and looking around, I purchased this router base insert, which looked to be the exact fit for the original routing. Using a drill press I picked up for free off of Next Door, I carefully drilled the holes in the plate, installed the undertable router base for my router (The Bosch one everyone recommends), and got it all working.
Router tables may not seem sexy or cool, but I am so beyond happy I got this set up!