Ok, so the interior trim code is just 216. The 401 is an option code that deciphers to singe seats up front. Before we get into the interior trim code, here is a deciphering of the option codes on your cars data card for for fun.
717 Papyrus white paint work
216 Cognac leather interior
401 Single seats up front
423 Power steering with Mercedes automatic transmission, column shift
461 Instrumentation in English
471 Special export version for bad road conditions with oil bath type air cleaner. ...this means stiffer springs are used that make the car sit higher than it should,
and the air filter being the oil bath type means you only have to periodically clean the filter element (soak in gasoline), housing, and refill with clean oil to
the mark on the air filter housing.
516 Becker Grand Prix Radio set, monaural. (one speaker)
525 Shipped with 1kg of single stage paint
531 Electric/Automatic antenna
540 Seat adapter between the front seats (This cushion would have been covered in Cognac leather, and would be where the wood trey would usually be
between the seats)
587 Folding arm rest on front seat
619 Halogen lighting units with bright light/dimmed light/fog light and headlamps and fog lamps and additional bright light, amber; asymmetrical headlamps for
Left Hand Drive traffic, and rear blinker lamps in orange for Australia, Italy, and Great Britain.
668 Mode of packing VE II, and with styropor bumper rails. ( this is how the car was packed for shipping)
Under the heading "Wenig Gewunscht" (not commonly asked for options) you have code 243, which is "elimination of battery". This means that the car was either to be shipped without a battery, or the battery was not placed upon special request due to subsequent modifications that were to be done to the car causing the location of the battery to be determined at a later time. Likely the former.
With the completion date of December 23, 1965, the car should be titled and registered as a 1966, as the car would not have arrived in Australia until months later in 1966.
Ok, so interior trim code 216. This tells us quite a bit! In the picture below, you'll notice under column 216 that there are rows of funny German words with numbers. The words are the color, and the numbers are the color code for the color. Each row is explained below
-In the first row you see 1505 Cognac. This is the leather color and the color code for the Cognac leather. Bear in mind color codes and trim codes are not the same!
-In the second row you see D 32 and Creme`. This is the color code and color name for the headliner material and sun visors.
-In the third row you see 6419 Dunkel Beige Melliert. This is the color code and color name for your wool carpeting, which is Mottled Dark Beige. (dark beige with darker colored flecking in the carpeting.....hence, 'Two tone")
-In the fourth row you see 2445 D braun. This is the color code and color name for the ribbed rubber entrance rail coverings, which are to be dark brown.
-In the fifth row you see Macassar. This is the species of wood normally paired with a Cognac interior....Macassar Ebony to be exact. Because there are no other option codes under the "Wenig Gewunscht" area would mean that the car should have Macassar Ebony on the dash and around the windshield. Sometimes people would specifically request a different species of wood instead of what Mercedes recommended.
-In the sixth and last row you see D 12 Graubeige. This is the color code and color name of the seat webbing strap color if the car had seat belts. Grey beige.
So you now know how your car left the factory. Though, if the original slim faced Becker Grand Prix is missing that will be a costly part to procure, but there are plenty of them out there.