The 911 and 912 seats of the same year are interchangeable.
You will need a adapter plate from the rails to fit the contact points in the car. you may have to drill new holes in the adapter plate to fit it to the car. Their (Cobra) seats are for the wider Porsches. Even the Recardo's did go from Ferrari, to Alfa, to Porsches without changing the rails or used adapter plates.
I doubt that very few early cars used their seats. Most have used/purchased, in the 912/911 community, seats from these folks. GTS Classic Seats. They have been selling to Porsche owners for over 15 years. They should have the rails that would fit your car. However, I don't know it they would fit you Cobra seats. Even though they do have the same style of Nurburgring Recardo's
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