Quote - You could use a ball to endcap the openings.
With the morphtool and some textures-displacement, it could work.
Or, open the exported arm hand-fingers obj in a 3D app, and close the remaining gap?
You'd still need some trick to close the gap on the collar :-)

I did something similar to this, doing the old lightsaber cutting off the forearm trick. Camera angle and the clothing hid the missing parts. I also did the duplicate character thing. Makes the render drag out a bit, though.

If I had a nickle for ever time a woman told me to get lost, I could buy Manhattan.