I have a small update: SL-C3200 Hitachi HDD is CF2 size (5mm thick) so I doubt there will be enough space for any BT module using original pins. So the original PCB is exclusive: Either CF slot with HDD (SL-C3xxx) or Bluetooth (SL-C1000). One cannot have both there.
But you can still solder flat wires there and place BT module to another place. It means, that you can use any module which supports 3V data lines and UART mode. Nowadays you can buy much smaller modules than the original WML-C19NHR, which don't require external voltage regulator and reset.
Here's my photo of the 6000's motherboard and the module I bought which turned out to be the wrong type.
Your module is probably WML-C09AHR (AIR?). This is a module without sound processor and PIO and it is pin incompatible. But it can still be used wit a bit of wiring.
Youn have not only to carry about model name, but also letters after it:
A=embedded antenna
H (if it is really H)=H4 UART
R=regulator is included
You have need to wire at least these pins:
Four data pins.
Power.
Reset.
If you want to know exact wiring, I can send you data sheets with details.
But if you can look at your SL-6000, I would be glad, if you could help to detect following parts:
Small quad-resistor pack near module data pins.
And if you could trace or get high res photo of wires to following pins, it would be very nice:
Two changer modules to BT module pins 21 and 4. Each should consist from one small 5-pin IC, one a bit larger PCB capacitor and three small unknown parts. They should be located near to these pins, maybe on the opposite side of the PCB.
Also tracing of exact wiring of reset (one transistor and one unknown small part) would help. Note that at least the WML-C19 requires reset to work.