Just got this in the mail.  I can't believe I found one.  Basically this walkman has an FM transmitter built into it so you can listen to your walkman on the Aiwa HR-S1 wirelessly...take that Bluetooth.  According to PocketCalculatorShow.com the Aiwa HS-P2 was supposed to have a similar setup but the FM transmitter was externally mounted, aka Aiwa HS-P2X.  When I get this one working, I'll post a video to show how it works.  Enjoy.

They're in great shape David! They look well cared for