I have had two different 66 sprint 200 mustangs and the interiors appeared to be the same as any other 66. the sprint package was only an engine dress up kit for the inliners to make them sell better because they were short on V-8 engines.
I can't recall exactly how the name plate looks, but I think it was a rectangular brass plate positioned below the radio. Another interior "thing" was that it was always equipped with a console.
Claes - used to be "FAST66"
64 Fairlane 500 project