Thanks very much for the advice; anyone with an old empeg Mark I manual PDF out there?

I don't have it handy at the moment, but the pinouts for the Mk1 docking connector are listed here in the developer's section of riocar.org. From there you can extrapolate the correct wiring.

And yes, the color-coding on the Mk1 wires is not the same as the "standard" color coding that's used for other aftermarket stereos. So don't go by color when hooking things up.

Also remember that since the Mk1 does not have an accessory wire, you are supposed to hook up its only power wire (I think it's the yellow one, not sure) to your car's accessory wire. That way the player will turn on and off with you car's ignition. The player also does not have a headlight-sense wire.

And since you're installing a Mk1 player, make sure to read this.