Here's my own (complete) scan of the Sony 1985 walkman catalogue in german: I also uploaded a lot of Sony catalogues to HiFi Engine.
Sony 1982.4 Japan The order might be wrong but what a beautiful catalog, thanks tas66dc! This is one of my favorites, I have most of these units including the super-rare M-1000B Microcassette with brown coloring (posted somewhere in the Walkman Section). I wish I could read it, I was surprised it's more money but I can't tell if there's something special about it besides the color.
This guy posted in the boombox section awhile back, his site has some brochures. He also has a ton of guitar brochures if your into that. https://catalogism.com/category/audio-video-components/
I was just going through my hundreds of bookmarks and found this dead Walkman Website, there might be some information you use, this page has some timeline highlights. Once these sites go, they can be gone forever and we lost dozens of great informational sites over the years. https://web.archive.org/web/20160406075212/http://www.sonyvintage.com/?page_id=1253