Of course you should actually mount your tool to the wall holder you are making. I traced the hole pattern with a cut off pencil. When drilling very deep holes, it is best to pre-drill with a smaller diameter and to work yourself higher up. I also addded a chamfer at the top to make it easyer to insert the screws. This turned out to be unnecessary, since I could not add any bolts from that side anyway.



I also cut a little relief angle to allow the bolt heads to sit on a flat surface. This can be done with any kind of saw. You are only removing a little bit of material, so it is easy.