Datsun 2000 Sports or early 240Z boxes (good luck......). To use a 2000 sports box, you will need to find both the 2000 sports box, plus an very early 240Z box to get the correct bellhousing to bolt it onto an L-series engine. The 240Z box is longer, and will position the gearlever maybe 4 inches further back in the transmission tunnel, requiring cutting and welding of the tunnel. Only the earliest 240z boxes will do for the bellhousing, almost are you come across nowadays are the later style with the same gearlever setup as your stanza box. BTW, only stanza and R30 skyline are the correct length for the shifter to come through the original 1600 shifter hole in the tunnel, all other gearboxes are longer.
I'm with Mr Midlife - save yourself the angst of looking for rocking horse teeth in a haystack, and do a cut and shut on the shifter, followed by a rechrome if you can't keep the heat affected zone within the gear lever boot. Whack the original rubber boot over the workings, and a 4speed knob on and no-one will be any wiser.
EDIT: Now that I've looked at the picture, someone has fitted an abortion of a gearlever to your stanza box to bring the gearknob further back (maybe some non-japanese-sized owner in the past didn't like the reach to the standard one). There are plenty of levers (bluebird / zed / stanza / 200B / etc) that should look much more like the original 1600 one. If I remember tomorrow, I'll have a look through my stash and see what I can find.
Also, looks like you shell has had a "long" box fitted at some stage - the transmission tunnel hole has already been enlarged.
EDIT EDIT: I've looked at doing something similar to what you want to do (adapt the early style shifter setup to a later box to get around racing regs that said I had to use an original box - yeah, yeah, call me a cheat, everyone does it, insert other excuses here
) - I ended up with a couple of half-dismantled gearboxes that didn't look like they were going to be happy being merged together and am now in the market for a 2000 sports box.