When you say Series 70 or 80, I am assuming you mean rather it has a firing pin block or not? Some people would argue a 1911 with an external extractor is neither since its not a "real" 1911 ().
I can't give you a definitive answer but I will tell you that my newer SW 1911 are (or have been) Series 70 and the older models (billboard era) are Series 80. I believe the switch from 80-70 happened with the introduction of the E-Series about a decade ago.
The lack of firing pin block which can be easily seen with the slide racked back...