Something seems a bit odd about the description of Nowakowski's opus 17 quintet "Piano Quintet No.2 in E-flat Major op. 17 (1857)" in a post from some while back.
From this link (http://hofmeister.rhul.ac.uk/2008/content/monatshefte/1841_12.html#hofm_1841_12_0180_11) it's clear that Nowakowski's quintet opus 17 was published by Kistner of Leipzig (without "no.2", as Grand Quintuor) in 1841. So ... nu? :D I can think of a few different reasons for the discrepancy (not just the most obvious one- maybe this is a quintet no.2 w/o opus (1857), e.g.)
(Apologies for typographical errors- for the moment and briefly I am reduced to typing with 9 fingers, more or less. It's a story. Eh. *shrug*)