02 C230K (coupe): "Driver's seat lock" message; seats not working

[pkor]

I've decided to do a nice carwash/detailing this weekend, and during the process I have noticed that the driver's seat stopped moving (as well as the steering column). When I've started the engine, the error message came up: "Driver's seat lock" with the picture that is supposed to indicate that the seat is folded and I need to completely unfold it. I've seen that message occasionally came up before, but it was always going away after I've folded and unfolded the seat. This time is didn't, though.
I assumed it is a sensor/switch that supposed to detect when the seat is folded. I could not find the location of that switch in my repair manual and spent nearly whole day yesterday looking for it - until a faint click it makes finally gave it away. I could not reach the switch, but I was able to track the wires that went into the control module, and attach multimeter - to my big surprise the switch was working. I don't know what else can be broken besides the control module in this case.
I really need some advices here:

First: it is possible to move the seat without the motor? It broke when I was working on the car, and the seat stuck in the worst possible position - all the way forward. I drove two miles on this car today, and it was a nightmare. Besides the inconvenience while driving, it prevents me from removing the seat, because the the front pair of bolts that holds this seat are covered now.

Second: do I need to look at anything else besides the control module?

Third: any advices on getting the right replacement module? My passenger module is broken already (power drain), so I'll have to replace them both. Those modules are quite expensive, and I had no luck in finding used ones on ebay. I read somewhere that modules from e-class are compatible, but I cannot find that thread anymore.