The round bung is most likely US Army they have different spouts to the usual German/English locking spout.
The numbers and letter on the side represent Standard, Manufacturer and year of manufacture so it looks like there's a 1945 and 1952 jerry can there.
ICC 5L = standard
cavalier = Manufacturer
20 5 45 =20 Ltres, 5 Gallons made 1945
Does the WD one have water stamped on it?