This movement goes back to a piano arrangement reducing
the third movement of the string quartet in Bb major
op. 5, no. 2 (B(enton) 311) composed and published by
Pleyel in 1784. The first piano arrangement was also in
Bb major (B 6524, no. 11). Later on it was sometimes
transposed to C major, incorrectly issued as a part of
a supposedly original piano Sonatina in C by Pleyel and
in this form copied again and again.
It is also unsuitable to randomly combine movements
from different sources, ...(+)
This movement goes back to a piano arrangement reducing
the third movement of the string quartet in Bb major
op. 5, no. 2 (B(enton) 311) composed and published by
Pleyel in 1784. The first piano arrangement was also in
Bb major (B 6524, no. 11). Later on it was sometimes
transposed to C major, incorrectly issued as a part of
a supposedly original piano Sonatina in C by Pleyel and
in this form copied again and again.
It is also unsuitable to randomly combine movements
from different sources, which have nothing to do with
one another, to form new fake Sonatinas.
Hence in the worklist of Pleyel there is not a single
Sonatina:
https://imslp.org/wiki/List_of_works_by_Ignaz_Pleyel