Thanks guys... I welcome tips and suggestions,
they're all helpful.
Casting from the Shapeways-printed object and
then modifying the resin copy is a good idea.
I usually end up modifying and touching up my
first resin cast object, anyway.
I can just use the Shapeways object as a template
to start the basic sculpt for things I'd otherwise find
impossible to sculpt from scratch with clays and putties.
As a hobby, I collect Japanese action figures and model kits
of anime robots from the '70s and '80s anime tv shows...
...some of my robot figures may need replacement parts,
or I'd customize some of my beat-up robots with my own
custom-made parts.
Then there's just the one occasion in which I don't wanna
modify a newly-bought robot figure, but I'll cast its body parts
to make a resin copy of the robot figure, or, I'd use the parts
to make enemy robots for the hero robot figure. lol