Sean, your pic is the right light that I am looking for and I suspect the one Steve is looking for as well. If the numbers are handy, it could possibly help but I understand what "packed away" means.
I hunted around, and it seems I have only two numbers, as follows:
I did not find a separate number for the base gasket, which is pretty much required. That may be because it is included with the housing, or it may be because I just forgot to write it down. However, once you give the parts dweeb the above numbers, he/she should be able to find the rest.
I had also remembered the lamp-holder as a separate item, but apparently not.
If someone runs down to the Chevy dealer to check these numbers out, post back here and let us know what you found out. One parts web site I went to said these fit '79-'95 trucks.