A very dear friend of mine is a congenital LBE (left below elbow) amputee due to a birth defect. I want to make a sim of her that properly reflects her real self. She doesn't wear a prosthetic arm very often so I didn't want her sim to have one. I understand that in game this would look odd because the sim would pick things up and it would just float there, but Sims use their right hands more anyway...
I've seen a headless skin before and I've seen missing legs so I know it's possible. I was hoping that it could be made as an accessory (glasses) so it could be used with different skins.
I've had a look around for you but couldn't find anything sorry. There's a glitch that makes the whole of a sim's arm disappear shown here and here
Someone has requested a full arm amputation over at GOS here
You might have to request it from other creators.
Theres a request thread on MATY (you have to be a member)
There's this thread that shows creators willing to take requests.