Daslogster:
While you are correct, the instructions don't have any details, RJS seems to recommend putting all oak in the primary for the length of the primary. The cubes are lumped in with the "oak powder/chips".
I haven't made this kit since 2006-2007, but my notes say that it contained "large oak shavings (OAK120, about 4 cups), Hungarian oak cubes (2ozs)". My wife and I really enjoyed this wine, and would happily make more, but it keeps getting overridden by other kits. (It doesn't help that I don't wish to deal with the two closest RJS dealers.) BTW, we did not add the shavings, just the cubes, as we don't love heavy oak. I think back then it was a 7 day ferment too.
Steve