I decided to use the single wire method to make the armatures for Larry's hands. Less connection points in the hand mean there are less opportunities for the fingers to break.
The lovely George Carman (blog here) gave me a great bit of advice. When you want to sculpt two things exactly the same its best to work on both pieces at the same time. That way you can roll out the same size bits of sculpt and apply them to the armatures at the same time.
I had originally planned for Larry to have five fingers. After mushing several hands in frustration I decided to remove one finger to make sculpting them a bit easier.
Larry's hands laid up in Plasticine ready for pouring the first half of of the mold. See below/