Looking at it now. I appear to have just dumped it to /usr/share/games/doom/prboom.wad
I'm checking the docs now for the command line wad switch
prboom [-complevel lvl]
[-width w] [-height h]
[-iwad iwadname] [-file wad1 ...]
that should fix it, or linking or dumping it in the places it wants it.
I would choose option 3.
the others are complicated by name needs. (working on resolving them)