so, i recorded a type 1, normal bias, on a 70s cassette deck, and it sounds FANTASTIC

I am surprised those old tapes still even work without jamming.  I am also surprised you aren’t getting “print through” on the tapes being that old.  

Cassette tapes were never designed for music.  Tape speed and size were for voice recordings.  Like lps.  Reel to reel tapes were designed Ed for music with limitations.   Dolby was a bandaid for the tape hiss.  Transistor radio to Walkman to portable cd players , mp3.  All compromises for audio on the go.  

I still listen to cassettes. On a Revox B 215. It doesn't get any more analogue then tape. Pre-recorded chrome tapes are fantastic.

*than

I also still listen to prerecorded tapes from the 80's primarily. They were the format.of the day. Have a big Pioneer CTF 9191 that plays beautifully. All in on analog, whatever the format, and they have held up remarkably well. And I have scored some real nice finds at my LRS for like a quarter!