1939 movement, date stamp shield.
1949 (49) 21 jewel
This movement is is 7AK not 7AP. Should it be posted here? Curious.
1943 - 21 Jewel (perhaps a '44 - looks to have two engraved symbols - an X and a O)
1937 example w/ 17 jewels. Arrow date symbol. Here's watch record for this movement.
1944 example, date code: Circle