Watch Case Removal tool

Needed a tool (other than my microcaliper jaws) to remove the case back from my Diesel watch to replace the battery. This is what I came up with, and it is functional, if not a work of industrial art. I measured my case back to be 41.4mm outside diameter and 38.4mm inside the lug contact points. Don't know how common this size is, but hope someone out there finds this useful.