Playing with wheels and 20 mm spacers. The Reproduction Fuchs 15s fit the back, but need another 5 mm or so to work in front. I kind of would love to have 15" mud terrains and throw chunks of dirt around the track rather than go for speed with stickies.
Fun thought, but probably going with 17s and 18s with 20 mm on the rear. Save the 15s with mud tires for 914 shenanigans another time.