Is it by looking at Behind the scenes pictures, or is it perhaps by watching the movie?
This seems like an obvious answer to me, but I better ask because there must be some other opinions, and also because the forum is kinda boring nowadays.
I would judge by looking at clear pictures or even before converted pictures.
Also..is it important for you that a replica contains words like 'Kirk' and '75'. I would say yes. It affects my opinion.