making a target to set at the close focus marking of the focusing ring; reinstall the front element; focus; replace the focus ring back against the stop; tighten the ring; and check the other setting marks to see if it all works.
Looks pretty close, except for the part in the quote, especially the bold. When you set the lens, on almost all cameras, including this one, you set it for infinity, not close focus. Put your ground glass or what ever you're using in lieu, on the film rails at the film plane. Ground side facing toward the lens.
Use a loupe or camera lens to get critical focus at infinity with a target about 100 or more yards away. Put on the focus ring so it's against the focus stop, and snug the screws gently. (The focus ring set screw on these Agfas break very easily.)
When that is done, all the focus distances on the focusing ring will be where they should be. Infinity is the one you have to worry about.
Most of us refer to this as collimating the lens, yes.
The Super Silette is somewhat similar to the Super Regant, but doesn't have a fold out lens, of course. The rangefinder
is quite similar.
Dean