Johann Gottfried Walther : Concerto based on T. Albinoni (1st movement: - Orgel manualiter)

Johann Walther adapted a large number of concerti grossi for organ like his cousin J. S. Bach, who was active for a short time (though in court service) together with him in Weimar. They made the most modern form of music making at that time which was also accessible to the organ.
Unlike Bach, however, he did not use the pedal so consistently, which makes it possible to perform some movements without restriction even on pedal-less small and chest organs.
The present concerto movement by Albinoni does not contain any indications of possible manual changes or a tonal gradation, so it can certainly be played on a single manual. However, there would also be enough time to push off and add one or a few stops before and after the middle section for a presentation that is not necessary but perhaps even more appealing.