I wondered if the deluxe version had a drain stamped in them,the 'cheaper' ones I bought dont.
Then I thought a $50 premium seemed a bit high for stamping a drain hole!
I think 1958GMCnut is probably nearer the mark as well.
As the guys say...give them a call!

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.