The sculpt does seem undersized from the pic. Looking at the bald Han sculpt I have and comparing to an Indy I have, the Han seems about 4% smaller. If you want, I can send the 3d model to you of the Indy I have, just to check.
Agreed. It's critical to get the scale correct before you start printing 100 sculpts.
Many good Indy sculpts were hampered by being underscaled, Buffy included.