Dropping a portion of the roof

[Fett]

I own a small, old 1.5 story (built 1927) that I'm about to remodel almost completely. I'm using HD Pro 6.04 to model it as accurately as possible so I can decide how to make the best use of every square inch of space before starting to think about additions. So far things have gone fairly well, considering some of the non-standard construction that this place seems to have compared to modern homes. One thing I'm having trouble with is the roof over the front of the house. Here's what I have so far:
http://kyarsgaard.org/images/floor2.gif
http://kyarsgaard.org/images/elevation.gif

What I'm trying to figure out is how to drop the front roof 10". The way this house was built, the main roof sits on top of the 2nd floor platform. The front roof however was actually dropped down into the platform. Theplatform had notches cut and the rafters are set down inside them. This causes the front roof to sit 10" lower than the main roof. As it is now, they're level at the bottom.

I've tried removing the front portion of the second floor, leaving a simple rectangle and building that portion of the roof over the first floor. The initial results were kind of messy, and not really correct since there isn't a wall there. Anybody have any ideas on how to account for this?