To clarify further in the calcs above I've made the conservative...

To clarify further in the calcs above I've made the conservative assumption that tax credits reduce tax payable, but don't affect the Govt take. If we assume that the Govt take is reduced by the amount of tax losses (which is one way to read the statement in the Good Oil presentation), then I get closer to $6.8m @ POO of $70 for the unworked assets. This makes sense in a way - without the tax credits the valuation is pretty close to $4m which is what Key paid, while on purchase there is an gain to Key due to the recovery of the tax losses.

Fully worked and realised could mean an NPV of $15m for the UK assets.

Not being an accountant maybe I'm off the mark here, but either way it's all a moot point, cause Kilwani is where the fruit lies IMO (I'm starting to sound like a broken record)