Definitely rough edges. There is a channel in the front. I tried to take some pictures with and without the existing front seal piece in the faucet to try to illustrate (sorry they suck). In order for me to take out or put back in the existing front seal piece, I have to go through the lever...
The piece would sit in the spout to seal the faucet lever. Like #3, front O ring, in this 525 drawing:
I'm going to try some Buna O-rings from McMaster, the 204 and a couple sizes up and down.
I've seen some other posts about these Insignia keg mystery brand faucets, and the advice is get...
I have a beer faucet that looks similar to a Perlick 525. There are no identifying markings, but the faucets came with an Insignia 5.6 Cu. Ft. 2-Tap Beverage Cooler Kegerator, NS-BK2TSS6.
I do not know the proper name of the piece in the pictures, so I'm calling it a seat washer. I cannot tell...