I popped to Maplins at lunch time to get some 3mm LEDs to light the eyes and headlights. They didn’t have any white ones though! I bought some blue ones which are 4.5v but ended up ordering some more off the website with matching 3.5v ratings which are two AA batteries. I used the fine tip on my soldering to make holes and slightly widen the joint shafts so the finger pieces don’t fall out… it appears to have worked:
The hands look good on the arms!