Unknown origin, from the estate of a family member. 

This is an antique stone or marble architectural fragment, in our family since my uncle was gifted this in the 1970s. 

Heavy, mounted and measures approximately 16" long (not including the mounting), 7.2" wide, and 2.5" tall. 

What I know: Vitruvian wave, above that a dart and egg design. Heavy, and reverse with an old green sticker that says 1911.66 (?) and Henry (cannot make out last name). 

As mounted on plywood or composition board, a yellowish ivory color and mounted. 

Damage from wear as shown. 

I have been told this is marble, then told, late Greek or Mid Roman, and told it could be revival - I am not expert! 

If you know by looking I'd appreciate an update!