I had my original rear coil spring laying around so measured them before tossing them out. Probably good to start with if someone was going to have custom springs made.

From a 1989 Townace 4x4. (pretty absolutely sure these are the same on the 4x4 US model)

Length: 13 3/8"
4 full coils
Rod thickness/diameter 17/32"
Bottom is ground flat
Top is Pig Tail

Bottom OD: 6 1/8"
Bottom ID: 5"

Top OD: 4 1/2"
Top ID: 3 3/8"