These are some photos showing us not only the factory original oil-filler necks, but other variations too as installed in 914-6 GT race cars. Take a look.
LeMans40 GT 001
LeMans40 GT 002.jpg
LeMans40 GT 044.jpg
Factory Oil Filler Neck - John Stroub 914-6 GT...
1970 Porsche 914-GT FIA World Championship of Makes 030.tif
1970 Porsche 914-GT FIA World Championship of Makes 031.tif
1970 Porsche 914-GT FIA World Championship of Makes 037.tif
Oil Filler Neck of the 1970 Porsche 914-6 GT FIA World Championship of Makes.jpg
1970 Porsche 914-GT FIA World Championship of Makes 038.tif