Funny you mention getting leather from a Sable. My Sable that was totaled a while back was black and had medium graphite leather seats and no center shifter. It would've been an ideal candidate for the swap you're looking to do. But, of course, I have no idea where it's at now.
I'm interested in seeing how you install the curtains you were talking about.
2005 Mercury Montego Premier--Current car
1995 Ford Crown Victoria LX--Current car
1995 Ford Crown Victoria Base--Beater project car
2004 Mercury Sable LS Premium--TOTALED by drunk driver at 89,000 mi.