I'm so pleased that this worked well for you. I had a lot of fun working out what the backdrop of Hogwarts' household management must entail, and thinking of how the elves' own status hierarchy might function.
I only wish I had a Carster of my own. But I imagine he had his hands full by the end of that year, managing Dobby as a subordinate. Hard to do that, when Dobby was fraternizing with the students. :-)