According to my friend Silvano,this kind of can was manufactured by the british, for the americans,never had a date on,and the letter J (jerrican?) was followed by a letter A,B,C,D, denoting different containt,plus 4 or 5 giving the capacity in british or american gallons.Some time there was nothing at all. He told me this story,but does not remember who he got it from.So I am passing it on,with a caution note attached:I trust him,but it could be B.S. for what I know.
WillysMB#344142 6-19-44 Navy N.S.Blue Grey
45 Bantam T-3 #57248 1-10-45
42 Willys MB-T #13560 11-42
43 Willys MB-T # 25417 4-43
Way too many WWII military tools,hopefully thinning down,and way too many posts...