We could consider a CFC ranking system similar to what Redscape does. It wouldn't be as easy to do since their entire site is devoted to Diplomacy, they have admin/GMs who devote themselves to maintaining the rankings, and their player tags/titles can only be changed by the admin when the player rank changes.
Here, the simplest thing would be to have one of us maintain a list just recording a history of our games: who won, who NMRed (and how many times), who abandoned a game with a debatable reason and who just walked away without a word. I'd suggest that the person to keep the list be someone who is both a long time community member and willing to keep the list up in the future. That person would simply have to keep editing and re-editing the first post in a thread devoted to this subject. GMs would PM new game info to that person and he or she could keep the data up to date.
Or, just play in Attache+ games at Redscape