Well, I have bought mine last year. While looking into the matter I learned that there are mainly 3 legit version:
1. The seagull 1963 produced by seagull itself(no visible case back)
2. The Redstar seagull which Thomas produces(
[email protected] mail him for prices)
3. The HKED version (this has a different logo other than that everything same)(website:https://www.hkedwatches.com/)
All have the same movement.
Now its upto you to decide which one you need.
The first one is from a reputed company and a little pricy .
the 2nd and 3rd are reasonably priced .