That's the pic that bugged me for a long time so I asked Ronnie and Herb about that last year - it was a customer car - NOT a second car.
Herb drove the Bird as a MP car and Liester? drove it as a SS car, I believe(don't have my notes in front of me). Didn't take much to change it back and forth, depending on where/who they had to race.
Reed in Ne.