Jester,
This is more complicated than I thought. Scarab Blue did not replace Corsica Blue until Sept '73 so your car should be Corsica Blue!
From James Taylor's excellent book on the P6 it seems that from Oct '71 to Mar '72 the interior colours for a Corsica Blue car were Buckskin, Ebony or Sandalwood and from Aug '72 to Aug '73 the options were Buckskin, Ebony or Mango. You can see that there is a slight gap (doubt) in between dates!
In theory, if the above dates are true, your car should have Sandalwood. And Ambla is the vinyl with little holes that was used as standard on the newly introduced "S" models.
Hope this helps and somone now offers you a set.
Regards, John.