Hi, I do not think he is a Buddha, he does not look like one. I would not call that glaze Celadon, it is just green glaze. Actually I have a very similar figure of a Budai in with a very similar glaze and similar technique, with front and back made in a mold and then put together before glazing. I never found out anything about it, but I doubt it is very old. Maybe Ipcress has an idea about it's age?
I also post some pictures of my piece for comparison.
Mat