Help! Ducktail Originality?

[Drew.Workhorse]

I've done a bit of searching, and can't find the answer to my question.
All I want to know is:

What years was the duck tail an option on a 911 from the factory?

All the information I can find says it was available in most markets except for Germany in 1974, and the Whale Tail was introduced in 1975, but doesn't say whether the duck tail was then discontinued or anything. I need to know because according to SCCA our 76 ITR 911S needs to have factory bodywork, and a duck tail is quite a bit cheaper than a whale tail and its rubber lip.

Thanks

[mspirito]

73 carrera and 74 carrera

[Drew.Workhorse]

Well that's a bit of a bummer, but thank you! I can finally spend some time trying to figure some other stuff out.