In this interesting quest for rare, everyone seems to focused on "hardware"; sunroofs, ZF 5 speeds, etc.
If you don't equate "rare" with valuable, wouldn't rare be some combination of model, PLUS a unique color combination? They had a huge palette of paint colors for the exterior, an unheard of today selection of interior colors, and some cars coming in "two tone" (different hard top color with matching wheel covers).
So it would be my guess that if you throw in the full color scheme, with model and maybe another option or two, you may find a number of "one-off" Pagodas...if it was production and one off, I guess that makes it rare. I don't know if it means much beyond that.
I'm not sure what it all means. There are quite literally a million different combinations of colors and options on a Ford F150, hardly any two are identical. I don't know if that actually means anything except headaches for production planners..