Early CCKW (up till about Sept 42) Thin black hard rubber 20 in diameter. 3 spoke, 120degs apart. Also used in Chevys
Sept 42 till approx Dec 42/Jan 43 Steel 20 diameter. 4 spoke. Thick wood rim, one piece hub/spoke casting.
Jan 43 ('early' 43) end of production Steel 20 diameter. 4 spoke. Two pieces... center hub with riveted spokes.
Wood steering wheels were painted OD (no natural wood showing).