Although sharing the Mü-13 model number with the Akaflieg München Merlin, the Mü-13E Bergfalke is a very different aircraft. As glider flying was at the time prohibited in Germany, the prototype of the Mü-13E was built by the Segelfliegergruppe Jenbach in Austria. The first flight was made as OE-0138 on 05-Aug-1951. Although the aircraft on the photo is painted as OE-0138, the museum says that it was built by FSC Giebelstadt in 1955/56 so this is probably not the real OE-0138.
This photo was added on 20 October 2019, and has since been viewed 35 times.