My LED collection so far.
The left column is all 5 mm x 5 mm square, single-chip LEDs. The yellow, green and red are for the back of the prop. Four orange will be used to make the 10 mm x 10 mm square on the front side in the upper right area, because I couldn't find a 10 mm x 10 mm 4-chip LED in this color (apparently neither could the makers of at least one of the original heroes -- in the Mark Dickson photo one of the emitters is rotated 90 degrees relative to the other three, something which could never happen in a production-line manufactured 4-chip part). Two orange will go in the upper left area between two red 10 mm x 5 mm 2-chip LEDs, again because I couldn't find a 10 mm x 5 mm 2-chip LED in this color. One orange will go in the back (behind the blue acrylic near the left side, because orange is the color on the front side in that location).
The middle column are all current-production LEDs that are close to the correct styles but not quite exact -- the LED dice are spaced on 6 mm centers instead of 4.5 or 5 mm like the originals. One of the red 6-chip LEDs will be ground into the ramp shape, to mount over the upper edge of the battery. I'm considering making an "idealized" version of the prop that doesn't exactly match any of the known hero versions, and if I do that, I'll probably cut the other red 6-chip LED down to 4 chips and 10 mm x 10 mm square, to mount over the center of the battery (instead of the square of red fluorescent acrylic), as shown in the Gene Crowell prop photo. The green 3-chip 16 mm x 5 mm bars are for the top center area, but I only have these two so far, out of five that the prop needs. I could build up fakes from clusters of 5 mm x 5 mm LEDs if necessary but I think that the extra glue planes might show too much. If you're reading this far you probably already know where the red 10 mm x 5 mm units go. I might use the green 10 mm x 5 mm units in a cluster to make that odd-shaped green area near the upper left, if I can't get a 6-die 16 mm x 10 mm unit in green.
The right column are what I have so far of the correct large 14 mm x 7 mm 2-chip light bars that make up all of the largest LED clusters on the front of the prop. I still need a bunch more of these. All in the photo are tested and working. I haven't encountered the problems mentioned elsewhere of some units being duds when new, or of being reversed polarity, although I have found some half-dead green ones (not shown) which were pulled from a circuit that drove them at 35 mA in a hot enclosure. They're only rated to 30 mA at standard room temperature, so it's amazing that only two dies were dead, from the handful of LEDs that I pulled from that circuit. I have noticed one apparent design issue, though. The yellow units I have are much dimmer than any of the other LEDs in this collection, even though they are new old stock, so I'll have to drive them at their 30 mA maximum, then calibrate all the others in the prop to the same brightness by reducing their current.
Long since lost though. I'll do a little digging & see if I can find anything. If memory serves there was quite a discussion about the lighting - it was identified but unavailable is what I remember...vaguely.
