Measure up first of all, going by eye will more than likly lead to a failure of some description. If within tolerance of std size bearing then bang in a new set, if not then crank out and send it for a regrind and get the appropriate sized bearings.
see what ya say about if in tolrences then use standard bearings but as for regrind this is abit of a no no for these cranks it seems that Mitsubishi put a special coating on and as soon as you grind it off the cranks dont last very long
thanks
andy