Never mass produced and/or prototype only.
HAVE:
Taito F3 Landmaker (World ver.) Prototype
I'm told this is the one that was dumped for MAME

WANT:
Taito F3 Recal Horn:
Don't know anything about the original hardware, but looking at the emu romset, it doesn't look too dissimilar from some of the earlier F3 carts, so reprogramming a standard F3 cart romset may be possible to get it running on real hardware.
Taito F3 R-Gear:
Said to have began on Taito F3 hardware and then moved to Sony's ZN-x hardware as a 3D variant (read RayStorm). More here:
http://shmups.system11.org/viewtopic.php?t=9928
Cave DoDonpachi Campaign Ver.:
You know the drill.
...
-ud