If it’s leaking above the base plate it could be: the tub seal, center post seals, rubber gaskets on the screws that hold the tub down to the base plate, air dome gasket or a crack in the air dome itself, last but not least is there could be pinholes in the outer tub.
If it’s leaking below the base plate it could be: the pump, rubber hoses, pump guard, drain hose. If the rubber hoses are leaking, you can use hose clams that you tighten with a nut driver or screw driver since the hose clamps that these originally came with have a mind of their own once they have been disturbed after many years. That’s what I did to mine 3 years ago.