I did have one for the MK3.sloopercat said:
If I did with the MK2, it's probably gone. Hard drive crash last year.
For the most part, take a ruler flat on the inside of the weel.
Measure out 3.5-4" from center.
This is where the bottom of the caliper will be.
So, from the ruler, measure *down* 1/4". This is the outside
face of the caliper. The face of the caliper is about 2.5-3".
For max diameter, it's 7" *minimum*, from the wheel center to the outside.
Aaron ran in to problems with the Epsilon wheels, as the locking nuts
were large.