Here is the information on my bucket. I'm guessing it is similar to most others. The tractor was parked on my bridge, one place that's very level. The bottom of the bucket and surface where the level was clipped onto are perpendicular.
Don't know why I didn't zero the level instead of starting at 1°. Duh. Anyway, fully rolled forward the bottom plane of the bucket went to 7.5° beyond vertical when the stops were hit. When curled back, it went 53.3° past horizontal. These readings were taken with the bucket fairly low, and should be close to reality. Since the arms weren't at exactly the same height for the three readings, there could be an error of a degree or two due to the arms swinging in an arc.
Please let me know if there are any other measurements or pictures you'd like.