Error and other envelopes

I have received two covers, one from Iceland and another from New Caledonia which were sent to Indonesia by mistake. Two covers from Gibraltar, one which came postage due, except that this was sent by the Gibraltar Postal Bureau, the guys who make the stamps forgot to affix it. Another Gibraltar cover with a large Indian Customs seal saying unopened. Yes it did come upopened.


Left: Iceland missent to Indonedia,
Right: Gibraltar Postal Bureau cover without stamp affixed

Left: Gibraltar cover with Indian custom seal (no error here)
Right: New Caledonia missent to Indonesia