Geoffrey, you didn’t imagine the post (see below).- I was that Englishman with a Luxembourg wife. I had to book a meeting slot online for our prefecture. I don’t know if your prefecture requires the same, and if they do it might be worth checking on their website since you typically get immediate confirmation of your time/date. You could then cancel your email request. As well as a slight case of pursed lips from the prefecture lady at my not having a visa (not required in my case) , I was also told that I should have had my EU citizen wife with me. This is not a requirement either in the EU regulation for this type of carte de séjour, nor is it on the Immigration Ministry website’s list of required items to ‘bring’ with you to the meeting. However it does make sense since it is obviously only by virtue of the relationship with an EU spouse that you can claim this particular carte de séjour.