You hit the nail on the head,
Unless you can achieve high payload factors on every sector (>70%) and good yield combined with high utilisation (+300hrs) it is virtually impossible to make money. Only way it can be done is to achieve economies of scale by having a number in yourt fleet and combining this with other services with other aircraft it is possible e.g. through using cargo capacity in passenger aircraft. The combined result can be good as you can achieve good overall yield.
As for AF 747 which Ocean is "suppossed" to have acquired. I think you will find they are not belonged to Ocean but to a leasing company in Austria or to a company based in USA