I wanted a satnav mount for my Z900rs. I don't have a Garmin but studying the images of the mount I thought I could adapt it to fit my Fodsport (don't laugh, it works fine for a ¼ of the price)
The hole centers were perfect, just had to drill out the thread and it bolted up perfectly. Solid, no vibration or wobbling about. I did reverse your fitting to be able to see the indicator repeater. Other than that, perfect.