I just weighed my powerball - it was 61 grams. I assume the extra 1.7 grams is the plastic bag? Looks like I have an original powerball
I clean mine with chrome cleaner (used for cleaning motorbikes/cars) and rub it all over with a scouring pad that is normally used to clean up sinks. Make sure that you wear gloves if you do clean it this way, as it will take the skin off your fingers otherwise. It soon gets dirty again after a few games though...