Summary

A device for inserting a 18V random orbital sander so that the edges can then be sanded at a right angle.

Only works with the model shown, but may be an inspiration for other models.

With a Kerf of 0.15, the file works perfectly with my P2.
The wooden parts must be glued together.
I have also adjusted the distance from the battery-pack space. 
For my version, I had to add 2 very thin wooden strips...