Setron's Profit's Triple! New Nation 1976, this is shortly after taking over Sony's Singapore Manufacturing, they were also building units for JVC and a few others.
The beautiful Sencor S-5000 from 1977, too bad I can't read it? Hi Fi Stereophonie Magazine (Germany)
AIWA moves to the Philips Cassette Format just before releasing the "first", maybe 2nd boombox, from Billboard 1967 January.
From Billboard 1973, some information about AIKO, whose founder started with AIWA. If you look in the newspaper ads thread there's a lot of AIKO Boomboxes from the 70's posted.
April 1967 Billboard, the grandfathers of the boombox, I think Sankyo Seiki is the motor manufacturer? It's interesting that Philips intended the cassettes to be stereo, when I was a kid in the 70's everything was mostly mono, then one day in the late 70's everything went stereo overnight.
AIWA Store in the UK 1978, this had the full line of equipment. They did the same in Singapore and I'm sure some of the other large cities around the world.