One thing that makes me suspicious about this drawing is that the first character, normally the three slashes, the top one either is completely underneath the “木” character, or pierces the top. This one looks like either sugimori intentionally squeezed the three slashes underneath the 木 character.
Source: google sugimori’s signature on PSA cards or check this thread out:
www.elitefourum.com/t/fake-ken-sugimoris-drawings/22004/1