1970 for the Canadian nickel-plated brass model. The later 500A and 500B models have green-painted steel fonts. (US production was 1940-61.) This per: Guide to Vintage Coleman Products: 1900-1983. ....Arch
Very nice man! I have a 1958 Canadian. Looks like your burner screws are in good shape, be gentle with them and maybe you can get them out if you ever need to.