When I was (re)searching about how to connect old keyboards I found the most useful information on Geekhack. Specifically there was this post about adapters you can order from the author.
Geekhack Forum
https://geekhack.org/index.php?PHPSESSID=duj5vfd709ef3svpe3ucgot6mulq3h1n
1 Comments
jaredj@dataterm.digital · 2 pts · 3y
Geekhack is indeed a good forum! Deskthority.net is another.