Also you'd get a logog following the opening credits ("brought to you by") and one at the end - two if they did one before previews. They were a real staple of pre-80's TV. I really wish classic shows would keep them on DVD.... Great stuff.
I love those kind of things too. The recently released early (pre-Barnabas) episodes of Dark Shadows have the original voiceovers during the closing credits. It's interesting because they always announce what big show is going to be on that evening, and it's usually something I've never heard of...something that maybe only ran one season but was their big news at the time. I'll go look them up at Wiki later. And at the very beginning they have the slateboard showing the VR and Original Air dates.
During one week of episodes, then President Lyndon Johnson's daughter was getting married. The voiceovers for that week advised viewers to tune into ABC that Saturday for complete wedding coverage "in glorious color!" Several scenes that week took place in the Collinsport police constable's office, and for that week only in the background you could see a framed photo of President Johnson hanging on the wall. Next week it was gone. Thought that was a neat touch for a 60's serial.
I agree, those sort of things are great for 'transporting' you back to that era.