Georg Wilhelm Saxer (? - 1740) was a German Baroque composer and organist. The Leipziger manuscript with signature Becker II.2.51 preserves three preludes and fugues by his hands, and two more anonymous preludes that are probably by his hand as well. They are very nice pieces in the style of the North German organ school. The prelude in D major is the longest of all of them. It is a nice piece, with a lively prelude, an even more lively fugue, and a solemn postlude, in long stately chords. The Manuscript shows in the prelude first a run of sixteenth notes on the regular paper, then a second run on a small piece of paper glued on one side over the first run of sixteenth notes. The first run is not crossed out, so it's not clear whether it is meant as a replacement or as an extension. The fugue took a lot of practice to master, but it's very much worth the effort. Again a great piece to get to know, and really amazing it isn't played far more often.
Though it's not a first here in the concert hall. Wolfram Syré played it as well: http://www.contrebombarde.com/concerthall/music/24557