I don't doubt your word at all BlackDog61. With all the versions and different configs (OS, settings, user permissions, hardware, etc.) I'm sure there will be many cases with the missing texture folder. I mainly wanted to point out there could be both possibilities. Only the my documents save location really threw me for a loop the first time I went searching for all my savegames. I now always save in that location because I use it to sync my savegames across all my devices sort of like a cloud game.Ah? I stand corrected then. I might have a now "old" PPSSPP version (1.3-146) - I haven't updated since mid-October.
In summary for the uninitiated, copy Danikk's "NPJH50681" folder into your PPSSPP program root ([PPSSPP Directory]/memstick/PSP/TEXTURES/) and also your current user folder ([Your Username]/Documents/PPSSPP/PSP/TEXTURES/). If any of those folders do not exist, you can create your own folder at that location. Note this is only for the HQ Optional Texture Replace; the iso rebuild still needs to be done using xDeltaUI.