b) Alternatively, do these pins exist somewhere on the PCB for me do put a solder blob on?
If anyone's interested I've got my Sheeva underclocked at 1GHz. You need to be comfortable with hand soldering surface mount resistors (0402).
Pull off R212, R209 and R2. Adding 4k7 across R3 will also drop your DDR clock down to 4:1.
Cheers,
Pete