Um.. er... that's a quad-axial equatorial-altaz mount - and why not !
Well done
But I am puzzled by the short exposures. My little LX5 compact - uncooled and unguided perched on a rock - gave optimal results using ISO 400 exposed for 60 seconds with the lens at f/2 - and was able to record mag 9 stars and the gegenshein at Mt Cook (NewZealand).
I would have expected a big current generation DSLR - guided and cooled would run to somewhat longer exposures than 15s.