Everyone is talking about Tanashin these days; are they the ones making all of the new cassette deck mechanicals? If I find something I'll post it here, feel free to contribute anything of value. They are still in business but there's no mention of cassette decks under current products. https://www.tanashin.co.jp/english/index.html
Some of the mech available to buy in 2001, it looks like all cassette mechanism production stopped in 2007. Tanashin TN-21Z Tanashin 217LG Tanashin TN-591R Tanashin TN-21ZW Tanashin TN-9X Tanashin TN-8S Tanashin TN-59R
From the Retro Kram Website and Kilobyte Magazine. (Lot's of neat stuff on this site) https://retro.wtf/
From the American Conservative Website https://www.theamericanconservative.com/articles/the-last-cassette-player-standing/
The Business Times, 1978 Singapore, Everyone's moving to Singapore and Tanashin has 50% market share!
VWestlife reckons the current "Tanashin" mechanisms are copies. Whether the tooling was sold, or some Chinese manufacturer just copied the design we will probably never know.
A more modern version, same company, this looks similar to a lot of nicer looking transports with pig-nose screws holding the door on.