I remember being confused by references to Gernsheim's 2nd cello sonata in some places as having two different opus numbers?
That's because he -did- write 3 distinct(?) cello sonatas (visible on his worklist @IMSLP)-
opus 12 in D minor ;
opus 79 in E minor (not an arrangement of the opus 78 cello concerto - the movement headings are different, the ending is in minor rather than major, it's just not the same piece- they may be related though. The manuscript's at SBB (Berlin) and at IMSLP now for inspection if you like...)
and finally, opus 87 (also in E minor apparently. Haven't seen it.)
now on their way from CPO
https://www.jpc.de/jpcng/cpo/detail/-/art/friedrich-gernsheim-cellosonaten/hnum/3860284 (https://www.jpc.de/jpcng/cpo/detail/-/art/friedrich-gernsheim-cellosonaten/hnum/3860284)
Please see this thread in the new recordings board:
http://www.unsungcomposers.com/forum/index.php/topic,6797.0.html
Alan Howe