I forget if I mentioned this, but the Diogenes Quartet has confirmed (https://diogenes-quartett.de/friedrich-gernsheim-cd-produktion-fortgesetzt-2/?lang=en) on their website that they have recorded Gernsheim's string quintet no.1 (with violist David Quiggle) and string quartet no.4. It's now in cpo's court :)
Thanks, Eric. Very good news.