I love checking out those old catalogs and info that come in some of the tape boxes. The style of illustration really takes me back. A bearded guy smoking a Canadian style pipe (long shanked) leaning back listening to reel to reel tapes in his Eames lounge chair,.. Oh, wait a minute! That isn't my memory, it's Doc's.
But seriously, in the 60's those reel to reel tapes were the elite source material just like today.
Be sure to check those RCA's to see if they're acetate (lots of the Red Seals are) and if so, treat them a little more gently. Even though they seem to exhibit a higher level of hiss, they can sound fantastic.
Here's a question for those who have collected a number of acetate tapes. I have quite a few now and even unplayed ones have little or no print through. Has anyone else noticed this?