Hand crank could be had through 1948, but I think hole disappeared earlier and crank just went past a little hump in the lower tank. Probably last actual hole about 1941, with the low radiator. Most early Ford radiators will have 2 big numbers, maybe a letter to indicate year stamped into top tank...like 19A, 99A...matching model prefix.
Dredging up an old thread. So, after some Google, Fordbarn, And HAMB research, it appears as I have had this '41 Merc "19A/MO" radiator in my stash for my '40 Ford project. I tried to mock it up in the '40 frame, and its not gonna work at all. At 21" wide core, and the mount flange holes being 24" apart it's just too wide for the 40 unfortunately. That said, since it looks to be designed for a '41 Mercury, will it fit the frame for other '41-'48 Fords and Mercurys? Since I can't use it, I want to be able to advertise it correctly and hit all possibilities.
A start: I don't know the '41 Merc body! I regard them as about the best engine donor for a '32! Sorry! But...'41 Fords used the fan on crank, so radiator mounted waay low sticking down through frame, crank hole was about 1/3 of way up radiator, and radiator mounting tabs were also maybe 1/3 up on radiator. I think it would be very easy on those to simply add brackets at bottom of radiator and put them into 42-8 cars. You should be able to tell from the brackets whether yours is meant to go through or on top of frame.
love these old threads he obviously misunderstood thought it asked your favorite drug idiot he probably was not allowed to use a knife and fork to eat in his home