I picked up this little gem at a vintage antique shop a few years back, the shop keeper said she was the original owner! It's not really a Walkman, it might be more of a boombox but it doesn't have a handle. There is a quarter inch cord on the back for an aux input and it has a really nice all-metal enclosure.
This little guy is a Sony SRS-F-10. The speakers do not detach, they have a small piano hinge holding them to the main body. I'm not sure what technology they are since they are just a hair over 1/4" thick and they have vents on the back side.
There are a few models that can be converted to some sort of boombox-walkman. One is the Toshiba RT-CS1, which I'm lucky to have brand new, boxed
I have a warm place in my heart for the Sony WM-57. It was the Walkman that started my passion to collect.