The entry on the 1967 German Ministry of Justice list for Feistenau says "Feistenau in Fischbachau, see Valepp". The problem here is that Fischbachau and Valepp are completely different locations, and are listed as two separate sub-camps. This is, in turn, replicated in the Wikipedia file. Consequently, I haven't been able to find out anything at all about this camp. Yet.