+1 to what RT said. Here's a pair of photos taken on Friday Aug 1, 1975 -- the beginning of a Bank Holiday weekend with CN running [ almost ] everything with wheels in the passenger department. It was my observation, admittedly limited, that by this time these cars were pretty much in the reserve fleet, and usually ran together as a 'set' or subset rather than comingled with 'conventional' cars; I'm not sure why this was, perhaps their electrical voltage or diaphragms. As you probably know 302 had some serious accident damage; I don't know that it was ever repaired, even though all five were xferred to Via. The four remaining cars are seen here at the rear leaving Toronto, together with a photo of one of the coaches, behind a GP40. Earlier that day the three interior cars had come up to Toronto in the middle of a 14 ( ! ) car train hauled by this and a sister '40. I can provide photos of the other cars if requested. 
Note that the CN emblem on the sides is significant metal.
Best regards as usual,
SZ
