Cover page bears the name “J. F. Schweiger”, which is crossed out and replaced with “J. D. Berlin”. The person in question is obviously the painter Johan Friderich Schweiger (1704-1788).
Another manuscript of this concerto exists in Stockholm, where “par locatelli” is mentioned on the frontispiece. The Fondazione P. A. Locatelli still lists it as an opera dubia in its edition of Locatelli’s complete works (2006).
The second movement, roughly transcribed: