firstly, are they genuine alps? do they have alps branding? they will be worth more money but i heard that this keyboard may have clones. secondly, its up to you. if you want to sell, i'm assuming its for some profit. it's more about the buyer i.e. can you find someone after the switches or the whole keyboard but sell it for a reasonable price? and what will you do with the pcb after the switches are removed if you do desolder them.
to test it with windows, you would need a teensy and to use TMK keyboard ADB (apple desktop bus connection)firmware. if you like the whole keyboard, i would recommend buying a teensy 2.0 and follow instructions on how to make the converter to USB, all you need is some prior knowledge as to soldering (if you can desolder switches, i'm sure you can solder 3 wires xD). i did this with my apple IIgs and it worked perfectly, and if your keyboard is standard ADB pinout (it should be) then i don't see why you shouldn't make it work on windows.
EDIT-
i see the alps branding now

. looks like SKCM whites / white dampened. you could always go to deskthority wiki and take a look for yourself (comparing logos etc and see what you think it is)
-Aran