There were a few models that would hold the Simucube 2 Pro E-Stop.  However, many did not fit the model that I have.  They also used quite a bit of filament.

This model takes a simple approach - create a plastic "plate" that can be attached with the standard T-Nuts and Bolts to any metric based extruded aluminum.  

This model is also flexible and will work with 4040, 4080, 8080, etc.  As long as the slot is the extruded aluminum slot is the standard 10mm, this can be used.  It may work with Imperial extruded aluminum too.

Print should take under 45 minutes.

Materials Needed:

2 x M3 nuts

2 x 12mm M3 bolts

1 X T-Nut

1 x T-Nut Bolt

Once complete, use your Bolt for the T-Nut to push the supports off - can only push the supports off in one direction, so make sure you push the bolt from the right side to easily push the supports out cleanly.

After that, press the 2 M3 nuts in to the recessed areas of the plate.  They are snug to create a good friction fit - may need something more solid than just fingers to push the nuts in the recess.

Next, attach the plate to the desired location on the extruded aluminum with the T-Nut and Bolt. 

Take the cover off of the E-stop ( 4 simple screws, and put the 12mm M3 bolts in the proper location (see pictures).

Push the E-Stop housing and M3 bolts up to the printed plate.  Screw in the M3 bolts. The E-Stop is now attached.

Put the E-Stop cover on and tighten the screws.

Done.

Pictures added for reference.