1:48 scale figures aren't "tiny"; the 1:350 scale injection molded sailors made by Tamiya are truly tiny. Harrison Ford is said to be 6'1", according to Google results. I think making the figure an even 1.5 inches tall (standing of course) would make life easier, though using CAD you can be as precise as you wish. I'd say you have managed to render a rather good likeness. To give some idea what is possible in the scale, you only have to look at examples such at the Richthofen brothers sculpted by Mike Good:
Model Cellar 1/48 scale Verner & Manfred Richthofen
Of course, Mike is working in clay and you're not, that must make a difference.
Regards,
Robert