Help with stepside rear side marker housing

[Carl Spangler]

My 1971 shortbed step needs the drivers side rear side marker housing. Most of the drivers side housing is rotted away. The passenger side housing is a little thin but savable. This is the 'inner housing' that the side marker lamp goes into.

Does anyone make these or do I need to scavenge it from a boneyard? I've searched the usual suspects but can't find it.

Here's a pic of the rear passenger side inner marker housing.

thanks