I think your best bet might be a Dewalt Power Tool charger. These are high-quality current-sensing NiCd chargers for *any* NiCd pack size from 7.2V up to 14.4V (or higher, depending on the charger model).

Just use aligator clip leads to jumper from the charger to the contacts on your batteries. Do not touch the contacts at any time while the charger is powered --120V may be present.

Of course, you still have to work out which two contacts are for charging.. maybe by probing the charger unit you have ?

Cheers