[Mondial]

Looks like the 10K resistor in early production was a #3524 which was rated at 1 Watt. Later production used the 9K which most likely was also rated at 1 Watt. So a 1 Watt replacement should be adequate, although going to a 2 Watt certainly could not hurt. Modern resistors are physically much smaller for the same wattage rating so they tend to get hotter when dissipating the same power.