This is the second lamp I’ve made using parts that Paula Mccullough (http://www.etsy.com/shop/PaulaArt) has sent me. For this one, I’ve used the white plastic and black rubber pieces of hers, and a metal shut-off valve of mine, and mounted them on a large chunk of wood.
I’ve included five photos at the end of this sequence to show how I usually mount the light socket when possible. I think this would work well with some of your ‘industrial containers’, Paula. Especially if you mount them on a board or chunk of wood. I only epoxy the sockets in (as I did here) if there is no way to use the threaded ‘nipple’, which comes in 36″ lengths (for about $2).
I’ll send you some parts when I send the lamps.