Kurt,
Took some attached photos of the rear LWB tail lamps that came into the US in the sixties.
Sorry these are used/abused units and not resto'd yet.
Although there are different part numbers assigned to the left vs right units, it appears Koito used the same basic stamping for both lamps, flipping over the RH unit, minus the cutout, to be used on the LH side: In the photos you'll notice the felted pad AKA "Filter" that's used as an interior drain/pressure equalizer sits on the BOTTOM of each respective unit. If you are missing the pad, the L-shaped tab will still be present to hold it.
As I am not the original purchaser of the trucks these appeared on, I cannot definitively say whether any of them may be from Stout vehicles. There are variations. The Koito part numbers appear on several of them, but those are marked as the later(Sept. 1968 -on) ISO units, vs. the J.I.S. units that were shipped here to the US. Those specific units do not have the raised nut behind each lens, but otherwise function the same.
Regarding the clear license-plate lenses, they all had a rectangular rubber gasket surrounding the edge of the lens, and all this was held in place by two different shaped tapped loose metal tabs on the interior. The tabs shown hold JIS: M3-.60x10 PHRHMS screws.
Also shown are the one-piece gaskets that both seal the colored lenses and cushion the unit from the valence. Shown there too is a metal OEM lens-divider AKA "Shade," to keep the dual bulbs from shining thru the neighboring part of the colored lens--these are typically rotted and long gone by now, along with most everything else.
Despite the many changes over the production of the early LWB trucks, I believe all the period-correct lamp units are interchangeable, just noting the ISO threads are different from the JIS.
Restoring the lamp units to functional status requires some ingenuity and creativity as you realize. The clear license lenses are curved to fit the shape of the stamped lamp housings, but thin Lexan can likely be carefully warmed in an oven to a molded shape. You can see with the photo examples, each one here was destroyed by the previous owners by installing larger wattage bulbs than the 25 and 25/8 watt originals, or by not seating them correctly within the spring-loaded sockets. Of course, it's much easier to delete the license lamp by forming a sheet-metal cover if relocating the actual rear license plate.
BTW, if you think these tail lamp units are hard to repair minus OEM or repro parts, you should try looking for the mid-range narrow tri-color units that appeared on the 1968-early seventies LWB trucks.
Same concept with the look-down license lens, but a triple color lens setup, however narrower that the later units that showed up on the FJ40/43/44/45 vehicles.
Photos to follow.
