The trouble with this set is pincushion distortion, with the
top of the raster bowed down and the bottom bowed up.
I’m not sure whether there is any adjustment for this, as the
lettering seems to be in German.
There are three adjustments provided to deal with this,
north-south amplitude (NSA), north-south phase (NSP)
and north-south symmetry (NSS). The three controls are on
the main panel, to the right of the c.r.t. neck when you look
in the back. If adjusting these controls doesn’t provide correct raster geometry, check for dry-joints on the controls
and nearby wound components and check C475 (0.27 0)
which could be defective.