90s bl? or maybe even before that timeline

https://www.mangago.zone/read-manga/patalliro/ (early 80s)

https://www.mangago.zone/read-manga/kaze_to_ki_no_uta/ (70s-80s)

https://www.mangago.zone/read-manga/challengers/ (1995)

There's some yaoi on this list too: https://www.mangago.zone/home/mangalist/395564/?filter=&page=5

Bonnasort 1990s https://www.mangago.zone/read-manga/bonassort/
Timeless melody 1960s https://www.mangago.zone/read-manga/timeless_melody/
Rumspringa no joukei 1980s https://www.mangago.zone/read-manga/rumspringa_no_joukei/
Night maze https://www.mangago.zone/read-manga/night_maze/
Love mode https://www.mangago.zone/read-manga/love_mode/
Tamayura https://www.mangago.zone/read-manga/tamayura_yuki_ringo/

Ah also https://www.mangago.zone/read-manga/beauty_and_the_west_chamber/