Getting Mac Address from known network

I lost my old router, and i need to know its Mac Address, only info i got its the log of my Mac (Yosemite), i have found that with this command i got a lot of info about the preferred networks (saved networks) on my mac.

defaults read /Library/Preferences/SystemConfiguration/com.apple.airport.preferences KnownNetworks

And it outputs something like:

"wifi.ssid.<77696669 2d756e65>" =     {
    AutoLogin = 0;
    Captive = 0;
    ChannelHistory =         (
    );
    Closed = 0;
    CollocatedGroup =         (
    );
    Disabled = 0;
    LastConnected = "2014-09-19 19:20:23 +0000";
    Passpoint = 0;
    PossiblyHiddenNetwork = 0;
    RoamingProfileType = None;
    SPRoaming = 0;
    SSID = <77696669 2d756e65>;
    SSIDString = "heeeyomywifi";
    SecurityType = Open;
    SystemMode = 1;
    TemporarilyDisabled = 0;
};

But i see no mac address :(, could this be done? or shall i search somewhere else?