Sunbeam VT60 Vista Radiant Control Automatic Toaster?

Is there a fine tuning adjustment for the shade control on this model. The bread is not being toasted uniformly under the same knob setting. I know some models have an adjusting screw under the knob itself; but, this model has a push button at the knobs center to lower the bread. Does not appear that knob pulls off.

There is a screw behind the crumb door at the units base. Not sure if this is the shade control adjustment or the spring tension for the raising and lowering of the bread. Any thoughts to fix shade adjustment.