So this model of OVP relay has three separate coils inside and today after pulling the relay apart and seeing no issues with burnt traces, I plugged the relay base back in with the fuse installed but no cover in place.

When the ignition key is engaged or the car is started all three of the relay coils are pulling it's respective contact plate down into place.

Is there any other troubleshooting I should be doing to isolate any issues that would cause the ABS light on the dash to stay on all the time?

The Mercedes part number on the outside of the relay is: 000 540 67 45

If that is helpful at all.

the only appearance i look for is the date on the relay. older than 8 years old, replace it. get a dealer relay, those in th aftermarket cause problems when new. replaced alot over the years and fixed a few abs lights like that.

check ABS relay under ABS pump cover