According to The Serrane Guide, at least a dozen different forged sets are known. The description is not very good, relying more on comparison of the original to a suspected forgery.
On your patient, take a look at the ornament on the right center. The ray lines are too long. The two rays to the right of the topmost ray should be shorter (the left one slightly longer than the right) and joined at the bottom. The ray below those should be a thin straight line that touches the frame line.
In a selection of odds and ends I found this stamp. I am not as naive to assume this is the real thing, since it is well known that most (like 99%) of the Suez Canal stamps one finds are fakes. However, I would like to know if there are some quick reference points so that one can check in a few seconds whether it is the real thing or not. I will keep it with my Egypt and related collection, regardless of this being a forgery or not.
re: Suez Canal Company stamps - how to recognize forgeries
According to The Serrane Guide, at least a dozen different forged sets are known. The description is not very good, relying more on comparison of the original to a suspected forgery.
On your patient, take a look at the ornament on the right center. The ray lines are too long. The two rays to the right of the topmost ray should be shorter (the left one slightly longer than the right) and joined at the bottom. The ray below those should be a thin straight line that touches the frame line.