It is one of the twelve symphonies that Ludwig von Köchel only knew by its incipit in the Breitkopf & Härtel manuscript catalogue (p. 10, No.
In his third edition of the Köchel catalogue, he dated it to early 1765 in London, and opined that the incipit showed the influence of J. C. Bach's symphonies.
Neal Zaslaw agreed that the opening was characteristic of J. C. Bach in his book Mozart's Symphonies, but questioned if this was a legitimate method of dating works, given that the seven symphonies of J. C. Bach beginning in this march-like way were written later than Mozart's stay in London, that Mozart himself used similar openings in later works (e.g. in the twenty-sixth symphony, K. 184/161a), and that this style of opening was much used by other composers as well in the period.
0") possibly derived from pieces in the London Sketchbook (K. 15a–15ss), Fischer believed that the use of trumpets and timpani would be more likely for a C major symphony like K. 19b.
The authenticity of this symphony is more credibly shown by the source attribution to Gatti in the Breitkopf & Härtel manuscript catalogue, making it plausible that it was among the six sent to Donaueschingen by Leopold Mozart in 1767.