In October 2016 Ebay seller gerni-rekord from Norderstedt in Germany was selling a supposedly 1993 Oman plate, top left in photo. It is not a 1993 Oman plate but it is NOT a fake either.
In probably the 1970s an American, I believe, had many plates made in Oman that were in the style of the late 1950s and 1960s private vehicle plates. They are not very accurate as most vehicles from the 1950s and 60s in Oman were Landrovers, Landcruisers, etc and most had the registration painted directly on to them.
They are however correctly painted by an Omani signwriter in Oman so that is pretty good.
Since that time the plates have been sold from collections of deceased collectors and now there is confusion as to what they are. Some people believe they are taxi plates, others that they are 70s, 80s or even 90s Omani plates.
This is what is so very, very wrong with fakes, samples, replicas and made-to-order specials. 20 years from now no-one will remember what is genuine and what is real! People will be buying crap all the time.
If you want to buy replicas and don’t care if your collection is full of unused plates that you have no idea whether they have even been in the country they are supposed to come from, it is time you stopped collecting plates and maybe tried stamps or anything else instead. Postcards are nice also.