In July 2016 Ebay seller privatmuseum from Austria was trying to sell this plate. It is probably a sample made in Israel in the 1980s and is part of a batch of the different UN agencies working there at the time. Others are shown in photo 51 on page 7 of this site.
The design of plates is extremely unusual and all these plates are mint. No-one has yet been able to provide a picture of this style of plate in use on a vehicle in the Middle East at that time and this particular plate may well be more of a fantasy design than anything that was actually used there.
I will leave it up to each of you to decide if is genuine or not.