Distinguishing SDR dongles

My setup is two dongles (1 - NooElec R820T and 1 - NooElec R820T2) into a single RPi being processed by 2 instances of dump1090 with one doing double duty to merge the streams into a single feed. I really need to be able to distinguish the two dongles so I can set the ppm error and automate the startup/shutdown. Has anyone successfully used rtl_eeprom (or any other method) to distinguish two dongles? I just need some reassurance this does work for both T and T2 models as well as the step by step instructions (i.e., unplug, reboot, plug in, etc. sequence and the exact command line to use for rtl_eeprom). Thanks for any help here.

It worked for me on both R820T and R820T2 dongles. (The EEPROM isn’t on the tuner, it’s on the 2832, it shouldn’t matter what tuner you have).
I don’t have exact instructions on hand because, well, I set the serial numbers once and I didn’t need to touch them again. It was something like:

stop dump1090

$ rtl_eeprom -d 0 -s 00040055

unplug and replug

Then I just specified the serial number as the device index for dump1090.

Thank you again obj! --Kevin