Digital caliper bed levelling jig for Rep (remix)

It is a remix of Willfly's great design: http://www.thingiverse.com/thing:455050
I took his idea (and Rhino's file) and adapted the thing to be used in a clone of a Replicator 2.
What I did:
- Increased the arms' distance.
- Lowered the screw's wall so it can fit easier.
- Modified a little bit the canals under the arms so the toothed belt could fit properly.

UPDATE: after playing with this thing for a few minutes I didn't find it very useful. I think it is not accurate enough for the ta