Thanks, I'll do that. After finally getting through to the BA holidays team on the phone yesterday evening, I was told there wasn't the ability to upgrade the Heathrow-Zurich leg to CE for both of us as there was only 1 seat, however I could upgrade both the outward legs (to Heathrow and Heathrow-Zurich), which I found a touch strange. Apparently the 1 seat turns into 2 when you do that. Anyway, at £300 each, we decided against that somewhat pricey upgrade.