Thank you, wood for trees situation. Actually, I had my Mum on the phone reading me the contents of the email. Logged in to Expedia it still shows 'NOSYNC', but a valid code for MMB does indeed appear in the second email from them.

Do you know if there's a cast-iron method for confirming that these are going to be honoured? My family just bought them to attend my wedding this summer (thinking the fares were a good deal) - so it would be a bit of a disaster, personally, if they aren't honoured at some much later date when prices are even higher.

I mean, I can see the reservation on BA.com now, so I don't imagine it's going to be a problem, but one comment above along the lines of 'these are usually honoured' means that I'm a tiny bit paranoid...

--EDIT: Apologies for duplication between this and earlier post. I assumed that hadn't posted, in fact it just took a few minutes.