One of the first cassette players from 1966, the Grundig C 100, for those looking for early tapes, the Grundig must be liquid gold! advertising music!
Found a cool early Standard (which was bought by Marantz in 1974), the SR-T137F from 1969. https://palette.ocnk.net/product/563
They've started dropping in price, I might pick one up. It looks like they came in black and silver? The silver looks good in the photos but it's very telling of the future colors of bbx's and stereo equipment.
And I didn't know that this was another cassette format which failed to win... DC International https://www.ebay.co.uk/itm/20515321...y4joam3p7K72qoTbVMYJPDko4=|tkp:Bk9SR565w8vBZQ
It's wild how there were so many different versions but we saw that with most of the tape media until one version won.