No, it wouldn't work; the serial port is different level-wise, there is no stereo decoding on the tuner module itself, etc.

In theory, given enough patience, you could make a board and feed a mk2 tuner into a mk1. The mk1 software expects an internal tuner though.

If you want a mk2 tuner, you really need a mk2. It's not viable in terms of time/effort to upgrade the mk1's tuner circuitry.

Hugo