I'm curious as to what you find.
I have a mizithra recipe somewhere and will look for it and post it when I find it.
I, too, wanted to make a mizithra because of my experience at the Spaghetti Factory...they grate it, like you like it. However, when I made it, it is apparent it is really a fresh cheese. I couldn't really reconcile how you got from what I made to a hard cheese that gets grated. Aging it doesn't really seem plausible.
Anyhow, I am very curious as to what anyone else says and I will go and find that recipe.