cevatt - not sure why you need my endorsement for your maths, but yes i confirm that 50 cps is available under the scenario that you set out.
What you can't say with any confidence however is that $1.55 will be the market clearing price for the buyback. it will only be that high if insufficient shareholders are happy to part with their shares at lower prices.
personally - my punt is that it will be more like $1.35.
