Unfortunately, fake transistors do happen, especially for good or expensive transistors. Often the lettering is a give-away - so find an example which is known to be legitimate and compare with what you have. Next, try running it at near highest rated power and see how it performs, and compare it to specs.
This example looks to me like it might have been used by the time of the photograph.
Just my $0.02 worth - not an expert opinion by any means. Good luck - and your uncertainty is exactly why I buy from a known source, so I don't have to wonder.