Maybe you should forget about the pier altogether.
If you have a decent mount, mounted on a decent tripod, you can easily stay aligned, like so many here do.
Drag out your set up and start getting it polar aligned, and when you know you have it right draw a tight circle around each tripod leg where it sits on the pavers.
Remove the tripod and in the center of each circle use a masonry drill bit and drill down about 12-15mm.
With that done all you have to do is plonk the same legs of the tripod into those drilled holes, you are now back to where you started, aligned.
Leon
