You are convincing me it's not Claire de Lune 'Edgard Van Belle' but your reasoning that it's not any kind of Claire de Lune is quite simply, wrong.
That is your opinion. It is not necessarily true; but, you are entitled to your opinion, of course. To be clear; sure, I could be wrong; but, I don't think so. My experience tells me that I'm probably correct. However, if you have more experience than I, then, maybe you are correct; but, so far, I'm not seeing evidence of that. So far, I'm only seeing an argument that I might be wrong, not proof that you are right. You are confusing the lack of variation expected in a division/cultivar/clone (in this case Claire de Lune 'EVB'), with the considerably more expected variation in a grex (in this case Claire de Lune).
I'm not confusing anything, actually. I've been in orchids for a lo-ooong time and Paphs have been my genus of choice for the whole time. As a result, part of my opinion is based on what I know of people and the ignorant and crazy things that they do to name tags(!), which of course, is the thing that motivated you to start this thread. A plant that is labelled "Paph Claire de Lune X Paph Van Belle" says to me that someone who was not very knowledgeable "gave" that plant the name, because to them, it looked the same.....without even realizing that they have mistakenly used a clonal name as a parental name. Nobody who knows what they're talking about and has a piece of Clair de Lune 'Edgard Van Belle' in their collection would ever write the tag as "Paph Claire de Lune X Paph Van Belle". So, my educated guess is that an inexperienced person "put" that name on the plant because it was their best guess.
A matter of fact is that green Maudiae type Paphs have been produced in massive quantities for the pot plant trade and sold without names or with incorrect ones for years and years. A LOT of dubiously identified green Paphs have been imported from Holland for our North American disposable pot plant market. It is reasonable to think that an orchid enthusiast has at some point purchased one (a NoID) and then wanted to have a name for it. Since there are way more green Paphs out there that are Maudiae based breeding (without the very dominant curtisii in the family tree), odds are that this NoID plant, which looks like a Maudiae hybrid (without the dose of curtisii), is a Maudiae hybrid (without a dose of curtisii). In keeping with John Boy's farm animal theme 
rollhappy.....if if looks like a duck and quacks like a duck and walks like a duck, it probably is a duck! This looks like a Maudiae type hybrid that does not have curtisii as close as a grand parent....but, what hybrid??????....who knows.
Claire de Lune is a cross of Emerald and Alma Gevaert. Both of these are half Maudiae. Alma Gevaert is the result of Maudiae crossed back to its parent lawrencianum, while Emerald is the result of a cross with curtisii. There is, thus, quite a bit of potential genetic diversity in a cross of Alma Gevaert & Emerald.
Yes; but, the contribution of curtisii wouldn't be completely absent....it is too distinctive. Just as you & your siblings are not identical, neither are all non-vegetatively produced Claire de Lune plants.
However, since all Clair du Lune plants have curtisii as a grand parent, I believe that more curtisii would be evident in the offspring. Indeed, there is no guarantee all Claire de Lunes would necessarily even be albas.
Of course not. For the purposes of this conversation/debate, we are only talking about alba breeding....eg. white/green versions of each species. (Although I've never seen a photo of a non-alba Claire de Lune.) To claim this is not a Claire de Lune, because you think it's not Claire de Lune 'EVB', is flawed reasoning, at best.
I'm not saying that it's not CdL because it's not the 'EVB' clone; I'm saying I don't think it's CdL because I don't see enough evidence of curtisii and I'm seeing too much evidence of callosum (one of the parents of Maudiae). It looks more like Holdenii (Maudiae x callosum), than Clair du Lune; but of course, I couldn't say that definitively either. It's easier to say what something is NOT, than it is to say what something IS and I don't think that this is Clair du Lune; but, what is it?....I don't really know....and neither do you....unless you do track down the original plant and find that there is a reasonable explanation about the screwed up name label......and that you can then figure out what the correct name label was supposed to be. This is not likely to happen....thus, my comment that you will have to be content with this as a NoID.
But I'll end this with a question. You stated above "Now that you know the tag is wrong, you'll just have to accept it as a NOID". Why will I have to "accept" this? On the contrary, I will do my best to find the original source of the plant, and, ideally, see the original tag. It may not be possible, but I'm going to try.
Right! If you do manage to do this, and you are able to dicipher the tag and learn the correct name, you should then have the correct identification. However, I'm not about to make a bet that you will be successful at tracking down this information. Odds are stacked against you; but, as you say, it's worth a try. You never know, you might get lucky. Good luck. It's always nice to get a mistake corrected and give a nice NoID plant its correct name.
