Target size/weight for them back in the day was 1 1/2 inch diameter, 165 grains without adaptor. The aluminum adaptors were around 25-30 grains, so 190-195 with screw in adaptors. Depending on the state of the grinding wheel at the time heads varied a little bigger or smaller.
After Delta bought the heads, and subsequently under Magnus and thunder valley different sizes were made by grinding them smaller. 110, 125, 145 were common as well as 150-160 full sized. There were never larger production heads made, just the bigger ones ground down smaller.
Dad made a very few one offs by hand in the '60s up to 2 inches in diameter but those are very very few.
R