I'm using an AT440MLa on my SL 1210, and I had to dial in by ear.
Being unfamiliar with the arm, and wanting to experiment with the on-the-fly VTA, this was the easiest method.
the 440MLa has lost a lot of the high freq issues (my issues) when mounted on the 1210 - its got balls now.
no clue where the marker is now, but the 'arm looks fairly perpendicular.