Here's the one all you Atomic Ranch folks have been looking for.  We recently acquired a few boxes of old stock (though they certain don't look new) Mid-century Modern Starburst back plates for use with Schlage A-series doorknobs.  These are the ones that were so popular int he 1950's and 1960's and have been MIA for a long time since.  Well here they are again.  These are all in a tarnished state, but were Brushed Bronze originally.  You can easily have them plated to match what ever doorknob you end up using with them.  They measure about 7 1/4" x 3 1/4" with an 8 pointed star they feature a hole in the center a little bigger than 2 1/2".  Most modern doorknobs will sit within this hole, and on top of the inner lip holding it all to the door.  Doorknob is not included.  You can order Schlage A series knobs from your local locksmith.  These small starburst will work with the standard 2 3/8" backset, but for best effect, I'd suggest at least a 5" backset.