I declare myself well and truly and finally done looking for ivory lamp cord!
I went to this place and they said they hadn't made it in years. I was about to leave when the lady said she had some 6-foot cords with the plug attached if I could use that. She said she'd give me a heck of a deal. What kind of heck of a deal? A buck apiece. I didn't even DENT the box these came out of-- this is only fifty!
(They threw in some old, 70's GE plugs for lagniappe.)
Full disclosure: I think this is 16-gauge wire but much thinner than a regular extension cord.