The bolt pattern will work, as 4.5" lug pattern is 114.3mm, but the offset is WAY too high... 6.25" is 158.75mm, and you're looking for something in the range of a 40 offset. =) So, probably just grab some 15" steelies from Sears or NTB or somesuch.
A set of aluminum's from a 1990's 929 or a Mazda MPV would probably work. I have 929 wheels for winter, myself. Just a few ideas for you. =)