Pickup SRA - starting from a 500x microscope

I am not sure if my Lyra Atlas has the right SRA. Can other owners contribute? I have bought a 500x usb microscope, but it remains hard to find the exact angle. It is easy to get the angle of the record (or platter - I use a mirror), but very hard to get the angle of the stylus. I use the Cooling Tech software but it does not solve my problems. Trying to estimate the angle I cannot set the crosses sufficiently exact, and end up with values like 88, 90, 94 - varying all over the place.
I have only taken a few pictures so far, and could perhaps improve them. Tips and info welcome.