I looked at the classics parts catalog and they do not sell the part I need. The LMC catalog does show a picture of my part but it’s greyed out and doesn’t have a part number. I called them and they verified they do not sell the part. I followed the link to Mongo’s website and left him a message.
Thanks for the suggestions. I’m afraid an old truck junkyard is going to be my only option. Does anyone know of one?

My dad always told me, "Don't force it, get a bigger hammer".