After Mrs Bach, was this Chopin polka written by his pupil, Charlotte?

Further to the recent Mrs Bach furore, we present a modest discovery by the pianist, Philip Sears:

I regularly check the public domain scores digitized and released each week by the Bibliothèque nationale de France on its Gallica website.  Very recently they released a set of four piano pieces published c. 1860 and ascribed to la Baronne Nathaniel de Rothschild, aka Charlotte de Rothschild, a pupil (with her cousin Mathilde and mother Betty) of Chopin in Paris.

I was playing these through, and amazed to discover that two of the pieces are identical to posthumous works by Chopin himself, which are listed on worklists as being first published in the 20th century.  They are the  Nocturne in C minor, B. 108, KK IVb/8, P 2/8 (1837), first published in 1938 and the Waltz in A minor, B. 150, KK IVb/11, P 2/11 (1843), first published in 1955 (per the Wikipedia worklist).

The nocturne in the 1860 edition has barely any dynamic markings, but the waltz has performance instructions that do not appear in the Henle Urtext edition.  I am not only curious as to how these pieces came to be published under another name, but also as to the provenance of the other two pieces in the set, a polka in C minor and a waltz in F minor.  I can’t match these up to any listed work by Chopin, but they are certainly in his style.  I have recorded the polka on my YouTube channel here:

And the waltz in F minor here:

I am not a Chopin scholar, and would welcome any information your readers could provide on this.  The BnF score can be found here.

Reply below, please.