I have the German 7,7cm lFK 1896 n/A Limber assembled. I still have riveting to go and a new back hatch will have to be fabricated but at this stage you can see what it will look like. The 7,7cm and 10,5cm limber differ in size, box interior layout and in details of the foot board mounts/trace chain mounts. One photo on the web page shows this contrast in the two similar limber types. The German/Prussian 1873 Bochsattel and harnessing are correct for both limbers. Most of this limber was found in Eastern Europe and the frame and original depot marked wheels in Germany. There is one other surviving 7,7cm Limber at the Belgium Artillery School Museum but it was altered in the Inter-War period for Belgium Army service.
This is the link for the web page: http://www.lovettartillery.com/7,7cm_leichte_Feld_Kanone_Limber.html
Always admire your commitment to authenticity. Though labor intense, the finished product, consistently near flawless, is the reward for those efforts.