Aha, should have recalled this. This is the "visible VIN" a requirement in the US to have the VIN number observable from outside the car.
From the list of changes:
VIN ending 7114, 23 Dec 1968 USA cars with the additional VIN plate on the windshield frame, to comply with US requirement for “public” view, per 49 CFR (Code of Federal Regulations) 565
The VIN under the intake manifold should still be in place.
To get back to close two topic. The two piece soft top handle was put in place for the 250 SL on VIN ending 5089, near the end of November 1967