So after taking a better look at what I was dealing with, it was realized that by disassembling both grilles I was able to use the cross slats from the 240z grille in place of the shorter slats. Only moddification that was required was 2 extra holes to be drilled on each slat to compensate for the extra mounting points. Here are some pictures
Here is a picture of the 240 grille with a piece of the 260. You can see where the last mounting holes are not present on the slats from the 240 grille.
half way assembled
Drilling
Grille assembled and ready for paint
RustO!
Primed and ready for paint
Finished