Sorry to disappoint you, from the image you
provided, it really look more like a nice fan cel
than a production cel, maybe you should provide a
larger scan of the cel.
I can point out a few things on this cel, first
the trace lines on real Gogeta cels are very thin
when viewing in person, on the tiny image you
provided, the trace lines appears rather thick,
so I can imagine how thick the line would look
when viewing in person.
2. The color is not correct, the shading on the
hair, jacket, skin tone is way too dark.
3. I honestly have never seen a cel that is
painted this high, this cel have been painted up
to the registeration hole, actually nearly above
4. take a look at image below and compare to the
5. Having a real sketch, does not guarantee
You can ask the Cody or Saiyanwolf who actually
own real cels of Gogeta, they will probably agree
the lines are very thin on their real production