Mark VIII wheels fit, I think some of the later Continentals (since they were common architecture with Taurus whish is also 5x4.25), not sure what years I imagine 1995 and up at least, and the New LS wheels should also fit.
Yep I'm pretty sure the LS wheels fit, I just saw this ad over at TCCoA
These are Shaguar S-type wheels, so I would bet all of the DEW98 platform wheels will fit, that means LS, S-Type, and New Thunderbird. (along with Taurus, and Aerostar!!)
One thing to watch though, this guy with the S-types says they don't fit our late spindles without spacers, but they fit the early ones OK (pre-92?).