I have 3 different .460 boxes. Two say “Made in United States of America” on the bottom of the back in the red & “Brass Made in Sweden” on lower left corner in the yellow. Lot numbers are G0422 which has the child warning, (in the yellow field not in the red field as shown here) and 762 which does not have a child warning. These lot numbers are on the right end flap as a black rummer stamp. Also the foot pounds on both is “8245”. Address is just Firestone Blvd
The box of mine similar to what is shown has “09610” rubber-stamped on the inner box & nothing on either flap.
Can’t read the printed code on the left bottom corner on these photographs but mine is “611330” & contains soft nose bulleted rounds. address is now East Firestone Blvd. & no zip codes on any of them
Fronts of all three are the same, with same headstamp on the case.
So guess is 762 earliest, then GO422, both being Made In United States of America, & then the Made in Sweden variation but other than that. I’m sorry I can’t help.
Welcome to the forum. where sometimes questions just can’t be completely answered!
I believe there is a Weatherby Collectors Assoc. Perhaps some one there can help? Hope you keep us in the loop.