Carlton numbering can be a little misleading sometimes, the Flyer above is on an H prefix, 1960, so 61 - J, 62 - K, 63 - L and so on. They went up to Y in late 60s, then from about 1968 the letter/5 digit form was dropped for (iI think) just 7 digits, until... 1972 when the W prefix (for...