Shaun here is one you can buy quite cheaply with free postage as well . it must have the battery case as the seller says he has tried the unit but it does not power up Sony TC-48 portable cassette player early walkman 1977 rare
I have one D6C (old revision with trough hole PCB), but's broken and in horrible condition. Playback to fast and so on. More for retrieving replacementparts or a 180° Overhaul project. But since you only need the battery compartment, i could be it. Though I have to admit that I want to get rid of the whole device and the leather etui (or what's left of it).
I am getting a TC-44 in the mail today with the battery pack. I will see if it works. Also, does the battery case NEED the cover to operate? I hadn't thought of that until yesterday. Of course, I can just order the 3D printed one.
It should work without the lid but it is worth having for completeness I have bought one and it is very good value for the money.
It will work if you hold the battery compartment to assure good contact from battery compartment to main unit. Its the door cap that keeps the battery compartment in place. So you need that part for sure
