Niko -- I'm not familiar with Gijs Hendriks. But your post piqued my curiosity.
I found this Hendriks album on YouTube, and I'm giving it a listen now:
Very nice!
Notes on the album's page on Discogs:
GIJS HENDRIKS QUARTETwith Siegfried Kessler (p, el p), Bert van Erk (b), Michael Baird (d)& guests Slide Hampton, Sonny Grey, Raul BurnetThese 1976-77 recordings are from the period with Franco-German pianist Siegfried Kessler.This quartet was together for a year and a half. Frequent guests at the time were trombonistSlide Hampton and trumpeter Sonny Grey -- both are featured here on two tracks each. Andthe legendary conga drummer Raul Burnet is featured on one track.
Made over thirty-five years ago, these are historical recordings from a particularly creativeperiod of Gijs Hendriks, which were never released. Also fine playing by Slide, whose stay inEurope was under-recorded. Recorded at Lucassound Studio, Hilversum, Holland October/November 1976 & January 1977.