I might jump on this issue that apparently has everything about Marantz in it. It was briefly mentioned in another forum as a definitive source of Marantz Equipment published in the mid-80's. It looks like they have other issues with other manufactures highlighted including an issue about Tannoy Speakers with a lot of information and photos on the bay right now. Unfortunately it's written in Japanese but I'm hoping it has boombox and personal cassette players in it. https://www.amazon.com/Stereo-Sound-Marantz-Japanese-magazine/dp/488073098X
Stereo Sound is published quarterly in Japan and is the definitive Hifi magazine in that country. Each issue is as thick as maybe 4-6 issues of a normal magazine. It's been around since the 70s and back issues are still widely available. As Boodokhan mentioned there is no English at all in these, but they are by far the best source for info on Japanese Hifi through the years. The January issue each year contains the Grand Prix which awards prizes to the top new equipment that year and also contains a Best Buy section that ranks all currently available equipment in different price categories. They also print special issues focused on one topic, such as the Marantz issue you linked above. I'm sure it's worth picking up.
Thanks Gibraltar, do you know if the Marantz Issue includes boomboxes and personal cassette players? Some of it was branded UNIX, Superscope or Standard. The Tannoy Listing has a few pages posted and while it is in Japanese it looks like they get pretty detailed with a breakdown of the equipment.
Looked up the index for the Marantz Issue here. Looks like it only covers home stereos. Stereo Sound is pretty much only covering high end home audio. I've never seen coverage of Walkmans or boomboxes unfortunately.
