Well, I took the dash of a buddy's apart to do a freshening up of the cluster. It became a major undertaking, since the mylar lenses for "temp", "gen", "bright" and "oil" disintegrated when I disassembled the cluster.
Anyway, there is a piece of green tinted heavier mylar, about the thickness and shape (only a bit smaller) than a standard business card with an extension along one long end that has a couple of angles and a curved area. (Sorry for the long drawn out description.....)

Can anyone tell me where this goes and it's purpose? I didn't get any pics of it during the tear-down, and for the life of me, I can't figure out where it goes. If it matters, it's a column mounted powerglide.

Thanks, in advance

That piece attaches to the back of the speedometer. You need to bend it into an arc so it covers the odometer numbers. It wedges in there somehow, but it's really tough to explain. I haven't had one apart in a few years. Here is where a pic would come in VERY handy, but I don't have one of that area. I do recall when you get it in the correct position, the curved area should be arced toward the numbers.

As far as the purpose of it, I assume its to amplify the light of the instrument panel bulb to illuminate the speedo cluster.

Thanks for the help on that Pete. Finishing up the cluster in the next couple of nights.

do you need the idiot light lenses? I have a few left over