Dursts came with a reversible 'forehead'(?) that contained
a 45 degree mirror.  If reversed there was a 'tv screen'
motif and sometimes the word 'repro'.

If you put film where the negative is supposed to be
and artwork on the baseboard an enlarger makes a very
good process camera, albeit one that only takes small film.

The mirror reversal on the Durst allowed peering back
through the enlarger optics for focusing, etc.

I have a Beseler and to use it as a 4x5 copy camera I put
a see-through ruler in the negative carrier and turn the
enlarger and adjust to the right scale factor and focusing;
use a pair of floods to illuminate the easel; and use
lithographic film so it can be handled under red safelights.
Loading 4x5 film in a Beseler neg carrier in the dark is an
unpleasant task.