W-7 have 4-pin contact, a simple test by covering the pin show that 2 pin are for the body(103P) to trigger the winding, while the other two are for the winder to trigger the (S or C) shutter and winding.
So, if FX-winder(2-pin) works on 103P, and W-7(4-pin) works on 103P and 159mm(of cause), then FX-winder should work on 159mm but without the continous mode. Just my opinion.
There are both w-7 winder and FX winder listed in ebay now.