How to identify a genuine Porsche RS Duck Tail

I have never been able to  tell the difference between a real Porsche Duck tail or a replica.  This is what I have found.

If I am incorrect in my research, please correct me.  I am genuinely interested to know the difference between a real and a replica.

The  Duck Tail  from the 1973 Porsche 911 is one of the most iconic shapes in automotive history.   It is not only  beautiful but functional as well.    The duck tail provided lightness , better engine cooling, and decreases lift especially above 80 MPH and higher.   Ten years ago , I can remember seeing them for sale for $1,200 to $2,000 and thinking the seller was out of his mind.  Who would pay such a high price?   Well in hindsight,  I wish I was that fool.    Today , these Duck Tails can be $5,000 to $10,000 +.  Since the Porsche Company always pushed the limits of technology,  they experimented with fiberglass for aerodynamics and lightness.   The Duck Tails were not made of metal skins, they used fiberglass over a steel or alloy frame.   The focus was to increase lightness  to aid in performance wherever possible.   I really appreciate their philosophy and dedication that has been consistent throughout the Porsche Brand.   The research and design that the engineers put into the engineering  of these cars is incredible.   The  range of options offered to decrease weight and increase performance available to its customers was like no other company in the world.

The 1973 Porsche Duck tail is the more sought after version.   The early production 1973 Porsche RS cars including the light weight models used an alloy or aluminium framed for their duck tails.   The alloy tails were lighter and are more sought after and valuable then a steel framed tail.

Above:  Real Duck Tails have drain holes located on the left and right edge of the frame

Above:  Notice the rectangle fiberglass patch over the steel

Above: Another Example of the Fiberglass Patch

Above:  Steel Frame Duck Tails have a curved hood latch bar

Above: The Alloy (Aluminum) framed duck tails have a straight hood latch bar that also adds strength.

Above:  Note the location of the license plate lights found on 1973 versions

Above:  1974 version with the license plate lights blanked off

Fun Fact:  The front spoiler and duck tail helped to  move the center of pressure back several inches which helps to improve the car’s stability in a crosswinds.

Duck tails are broken down into 2 years:  the 1973 duck tails and the 1974 duck tails

There is no part number on the tails as far as I know.

1973 Duck Tail

• Porsche made alloy (aluminum frame) Duck Tails and Steel Framed Duck Tails
• All 1973 , have cut out for license plate lights.
• Drain Holes on left and right edge

1974 Duck Tail

• All 1974 Duck Tails are Steel Frame
• The ’74 does not have the license plate lights inside the trailing edge like the 1973 Duck Tails
• 1974 Duck tails can come with and without licence light cutouts. If they have a cut outs in the frame. The factory screwed small block off plates in place to close them off.
• Drain Holes on left and right edge

Then there is 1973-4 vintage fiberglass mat. And later NOS pieces that have a finer filament glass mat.  I could not find pictures to differentiate the two.

Above:  A Seller on Ebay has restored an original Duck Tail and asking $9,999.99 US Dollars

Above:  A seller on Ebay has a 1974 Duck Tail for $6,995 US Dollars.   Although rare , the 1973 tails and the alloy tails will command the most money.