Re: Quantum Mechanix 1/6 Star Trek The Original Series Kirk and Spock
There are some generic bodies now where you can pull out the forearms or lower legs completely, so if they used one of those they could simply sculpt a new forearm and plug it into the slot.
I don't think it would be that big a deal. There are plenty of good examples of existing figures where the manufacturer took the time to provide detail on exposed areas such as the upper body. Star Trek is a very special franchise, and it's important that the company producing these figures takes the time to do each one properly.
There are some generic bodies now where you can pull out the forearms or lower legs completely, so if they used one of those they could simply sculpt a new forearm and plug it into the slot.