Spacer for Plantronics W440

A friend asked me to prototype a spacer for the USB charging dock for his Plantronics W440 headset. His request was for a simple block with a recessed screw hole that he could then use double sided tape to attach the charging dock. I told him I would make that but that I also had some ideas for an improved version. Included here are both versions.

Plantronics mk1 v1.stl is the simple block version.

Plantronics mk2 v2.1.stl uses the simple block version as a base but adds a clip to hold th