Phony Benoni: <qqdos> I can't solve the mystery entirely, but here are some suggestions.Just to be clear, we are dealing with these two games:
Round 1: M Gerusel vs F Kuijpers, 1969
Round 2: F Kuijpers vs M Gerusel, 1969 (this page)
First, that they played two rounds in a row with reversed colors is not a problem, since this was from a team match where they would reversed colors in each round.
Now, as to the duplication in scores, I agree that this is too much of a coincidence. Looking at the opening repertoires of the two players indicates that this round 2 score is probably correct, since Gerusel often played the Nimzowitsch Variation (2...Nf6). On the other hand, the Round 1 score is the only game we have where Kuijpers used the variation, so if either score is wrong that would be the suspicious one.
Also, the supposed final position from round 1:
is hardly resignable for Black, as Geusel shows here.
So I feel we probably have an incorrect score for round 1, but finding the correct score would take a bit of research.