How's your cold...I hope that I don't get cooties conversing with you through the forum.
You're correct on the fitment issue with the Ghia.
The rear has an full inner well that is a little smaller than the body. The body is also
tapered toward the rear, as on the 914.
Any 5.5x15 wheel with a back spacing of 4, 1/2" to 4, 3/4" will work, especially when
lowering the rear about 2 notches. It has an IRS, so there isn't an issue as with the
swing axle fulcrum plates.
Hope you feel better.