Well the crack in the end plate has been glued and strengthened with a steel plate. Another lug is a bit cracked as well.
2 more hours in the oven didn't make any real difference and the leakage is just under 1 mA, but the log splitter works fine and doesn't trip the RCD. It runs at about 400 W when the motor is running but the control levers are released. It peaks at about 2.4 kW when the ram is deliberately stalled. Both those powers seem about right.
Of course, it hasn't been anywhere even vaguely damp since it was dried out and it may be that the insulation will degrade with time. If so. I'll almost certainly get a new motor.