SP/SSW 80' baggage cars w/ monitor roofs on the SP

I have some 80' baggage cars from Concor and wondered if the SP ever ran them. I've found baggage/mail and horse car pictures online and in some of the references I have, but no baggage cars with monitor roofs, most of the baggage cars I've seen were the 60' harrimans.

 

So what is a "monitor" roof.

 

also known as a celestory roof. I've seen them called this on the passenger car indexes on the web.

 

Okay, I wasn't familiar with the other name.