First post on this site, happy to have found it.
Based on the Spong Coffee Mills: A Grinder for the 23rd Century thread I found a Spong No4. Having used it for a few times I can conclude that there is a massive grind retention in my unit. 14 grams goes in, 8 comes out. I know others have posted on this topic before, but the threads are closed. Has anyone found a cure for this?

/The Priest