My 12 foot skeleton fell over and took out my streetlamp.  When choosing the replacement, I knew I wanted to add a USB port to power my Wyze cam instead of taking up the electrical port with a plug in converter.  I decided on using one of these: www.amazon.com/gp/product/

Unfortunately, there was a small lip on the lamp where I wanted to mount the panel so I designed this simple spacer to fill in the space.  It is parametric so it should be easily modifiable to anything similar that needs 0, 1, or 3 mounting holes along the centerline of the spacer.