& grace notes suggested by the editorsIn AsI the ornament, added probably later, is provided with a draft and not entirely clear form; however, it is most probably 
. Chopin would often use this mark in the sense of 
(at times they are even difficult to tell apart). Therefore, the use of a different mark does not have to mean that Chopin envisaged a longer ornament.
Placing a under the third in FE, which, formally speaking, changes its meaning, is a routine manner of the engravers, who would often move marks (concerning particular notes, but also slurs) to the side of noteheads (in the editions the stems of the notes in the 2nd half of the bar point upwards). Cf., e.g. the Polonaise in F
minor, Op. 44, b. 10. The absence of this in FESB is most probably an oversight.
None of the sources includes a mark that would specify the sound of the ornament's top note. The prevailing key in b. 184-190, F major, requires the use of e2, which in the main text we indicate with naturals. Omissions of accidentals in similar situations is a rule rather than an exception in Chopin's pieces – apparently, the composer believed that the sense of key would suggest the right note to the performer.
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources; Editorial revisions; Corrections & alterations
issues: Errors in FE, Placement of markings, FE revisions, , Errors in FESB
notation: Ornaments