I hate to say it, but I think the popularity we have been seeing for 'Eclat' has a lot to do with Nick Curtis's freeware version. Evidently this typeface is older than Doyald Young's version, because Nick gets a lot of his lettering from old font books from the 30's and earlier.
I think we talked about this with at least indirect participation from Doyald, but I admit I don't recall the 'punchline' about the origin of the font.
Actually Nick Curtis's freeware version is directly based on Eclat and not on an earlier source. This is Nick's note on the font:
"Another phine phont phorwarded by Phil --- Letraset Eclat --- provided the inspiration for this addition to the collection. A mover, a shaker and a money-maker, ideal for when when you want to make a strong but elegant statement. The name? Eclat � �clair � Creampuff � seemed like a natural progression to me."
Thanks Sander. I know he provides notes, so I am remiss in not reading that one. For a long time Eclat was not available except in the Image Club Letterpress. Letraset had apparently never digitized it. The Image Club version even had an alternate version, which I don't see anywhere now. The f, g, k, r, y, z, W and Y were different. See sample below, which will be added to the Script Font ID Guide ASAP. 
Captured from web.archive.org on 16 May 2005. view this capture