Here's a gorgeous "Circular Brilliant" which is extremely similar to an Old European with some very small distinctions

GIA is quite particular about what is an Old European Cut with it needing to fit three of the four of the following criteria:
Table size: less than or equal to 53 percent
Crown angle: greater than or equal to 40 degrees
Lower half facet length: less than or equal to 60 percent
Culet size: slightly large or larger

These parameters derived from historical definitions of the old European cutting style, staff observations, and discussions with trade professionals. Truly they created this cut so that old stones would not be graded poorly due to modern standards.

GIA uses Circular Brilliant for the diamonds that were in the transitional period - so stones that are not strictly European Cut, and yet not quite modern standards such as this stone.

We know the table size is spot on. The culet size is good. What the Diamond Dossier does not tell us if it was the crown angle or lower half facet that brought on the circular brilliant cut grade.

It doesn't matter what, the stone is gorgeous - there are no abrasions or chips. ! It was cut right here on 47th street.

Totally colorless, with that Medium blue. The stone always appears impossibly colorless - maybe a bit of blue? Not a hint of dullness. Tons of fire.

VS1 clarity, nothing to talk about there...

The stone is laser-inscribed by GIA.