IWC stands for International Watch Company and is one of the only hand made watches in the world.
By many, considered as the Rolls Royce of watches.
It is not unusual for a watch to have a plastic case ring but very common with fakes or lower end watches.
Your watch has a mechanical movement and a self winder making it more likely to be real.
However it looks like a promo watch made for Wimbledon, hence a lesser quality mass produced item perhaps used as giveaways.
Google the case number and see if you can compare movements in pictures.
