I can relate HF, the amount of times people have heard me say I'm giving up smoking just to see me go back... Now I tell people and they don't make a fuss or point out all the times I've said it before, I certainly don't get any 'well dones' anymore but it doesn't matter because I know that I've quit forever this time. I had this huge sense of relief when I said 'I quit' about drinking too, and only one person has questioned me on the timescale. Most people won't think about it.
To be honest HF, I think that if you actually want to get back with your ex then you should be honest. Don't make a fuss, just say you have quit and wait to see what he asks and answer honestly. I've heard people say that you need to prove that you are not drinking by your actions not your words, but that doesn't mean to say your words are worthless. If he was ever concerned about your drinking he will be glad to hear you have quit. And if he doesn't belief you, it doesn't matter because time will prove that you have quit for good this time. You've been sober a long time now, have some faith in yourself and others will too.
I hope it goes well whatever you say xxx