I believe this list to be complete and in general order starting with oldest (1983 ?)to newest. I just purchased a CP-S710 from UK the last model made.
Feel free to post pictures of your Kenwoods in this post for additional visible reference.

KENWOOD

CP10 KENWOOD PORTABLE WALKMAN cassette
CP20 KENWOOD PORTABLE WALKMAN cassette
CP303 PORTABLE WALKMAN cassette
CP303B KENWOOD PORTABLE WALKMAN cassette
CP3X KENWOOD PORTABLE WALKMAN cassette
CP505 PORTABLE WALKMAN cassette
CP505B KENWOOD PORTABLE WALKMAN cassette
CP5G KENWOOD PORTABLE WALKMAN cassette
CP5R KENWOOD PORTABLE WALKMAN cassette
CP60 KENWOOD PORTABLE WALKMAN cassette
CP700 PORTABLE WALKMAN cassette
CP707 PORTABLE WALKMAN cassette
CP707R KENWOOD PORTABLE WALKMAN cassette
CP80 KENWOOD PORTABLE WALKMAN cassette
CP9RC KENWOOD PORTABLE WALKMAN cassette
CPC7 KENWOOD PORTABLE WALKMAN cassette
CPC7B KENWOOD PORTABLE WALKMAN cassette
CPC7WH KENWOOD PORTABLE WALKMAN cassette
CPD3 KENWOOD PORTABLE WALKMAN cassette
CPD7 KENWOOD PORTABLE WALKMAN cassette
CPE5 KENWOOD PORTABLE WALKMAN cassette
CPE7 KENWOOD PORTABLE WALKMAN cassette
CPF5 KENWOOD PORTABLE WALKMAN cassette
CPF5BLK KENWOOD PORTABLE WALKMAN cassette
CPG5 KENWOOD PORTABLE WALKMAN cassette
CPJ5 KENWOOD PORTABLE WALKMAN cassette
CPJ7 KENWOOD PORTABLE WALKMAN cassette
CPR3 KENWOOD PORTABLE WALKMAN cassette
CPR730B KENWOOD PORTABLE WALKMAN cassette
CPR750 KENWOOD PORTABLE WALKMAN cassette
CPR950 KENWOOD PORTABLE WALKMAN cassette
CPS550 Walkman cassette PORTABLE
CPS710 Walkman cassette PORTABLE

Will post better pictures when my CP-S710 arrives.
CASSETTE RECORDER, PLAYER WALKMAN, AM/FM RADIO, AUTO REVERSE, Preset RADIO STATIONS, LCD DISPLAY,
Dolby B, 2AA batteries attach bottom like WM-100 series.