Rick, I agree with you that the nigrescens is not a typical fairrieanum. It has a very untypical colour, but that's (for me) the only difference. The dorsal looks relatively small from the drawing, and yes, it reflexes forward, including the typical fairrieanum waves in the upper third. It does show the small bract too. The petals recurve backwards. The colour of the dorsal and the pouch were described as "dark wine-red", whilst the petals were "dark reddish-purple".Carsten, look carefully at the line drawing of nigrescens from March 1975. You will see on the side view the dorsal clearly reflexes forward. Nigrescens is not your typical run-of-the-mill fairrieanum. Bernd's flower fits well within the above description of 1978 publication.
When I loaded the whole article above I was able to click on the individual pages to maginify enough to read but from work I'm not able to. I'll have to read the article from home and see if it goes into detail for nigrescens to shed more light on the topic.