What grades of Hamilton pocket watches have 4 Footed dials?

Larry, these are the models according to the information I have found.
Models with only 4 foot dials: 960P, 961, 962, 963, 964, 965, 966, 967, 968, 969, 970, 971, 973P, 976P, 977P, 991L

Models with both 4 & 3 foot dials: 950, 952L, 954, 960L, 972L&P, 973L, 974L&P, 975L&P, 978, 990L, 992L, 993L
The transition from 4 foot to 3 occurred between mid-1911 until late 1915 with most happening in 1912 and 1913.
Bob

Thank you Robert for this information.

Larry to my knowledge all 16s Hamilton's before serial number 875000 (this is a rough estimate as the different models may have been slightly higher serial number) were 4 post dials.

Harry