This quote is taken from this quality article:
I now wonder who that client was. Could it be the owner of the yellow and green one mentioned in the F400 club article:
When doing further checking I found this blog:
That's highlighting the following: "and two Ferrari 400 models undergoing restoration for a Middle Eastern client who just loves the type and wanted Ferrari itself to carry out the work"
So apparently it's someone from the middle east, but whom?
The following blogs shows other 400s at Ferrari Classiche:
As Always, the 400 is politely on the background: