Henning, SD7 is right. 9283042 and 9283405 are not valid IMO numbers, they don't exist.

If the first 6 digits are 928304, the seventh digit can only be 5. And Zephyr's IMO is 9283045.

Hi, everywhere it says "De Neus - IMO 928 3042"
For Zephyr it's 928 3405

This IMO number is incorrect. The check digit for 928304 should be 5, and this number was assigned to a US passenger ship ZEPHYR.