@Krieghund:
In the case of UK, the picture is complicated a bit by its dual economy. The requirement for the physical repair capacity is the same, but the source of the resources is different. Per the rules I quoted above, an economy that has a captured capital may not do repairs, and the two economies make their own separate purchases and repairs. If the repair is being done at an allied naval base, it doesn’t really matter which economy “pays” for it (the units don’t belong to a specific economy once they’re on the board), so this can be done if either capital is free. However, the rules I quoted prohibit the repair of units by an economy with a captured capital, as well as the use of resources from one UK economy with the facilities of the other, so that rules out repairing at a Europe base using Pacific resources, and vice versa, if either capital is enemy-held.
So, just as an example, suppose that India is held by Japan but the Philippines are still held by the US and Kwantung by the UK (admittedly, this is quite unlikely). Now if a damaged British battleship ends its turn in SZ35, next round it will be auto-repaired by the US naval base, and we’re assuming that London pays for it even if the amount is 0. However, if the damaged British battleship ends its turn in SZ20, it will not be auto-repaired because for some reason, London can’t pay for it now. I think that’s quite strange - if London is doing the repair at the US base, why can’t London be doing the repair at the UK base? I really see no reason why Calcutta (which admittedly can’t do repairs at that time) is now suddenly supposed to provide the money. They own the base, not the ship.
All in all, I’m glad that such events are unlikely to happen frequently.