With the second floor lined up on top of the first floor, I marked the outline of the porch soffit with a pencil. I wanted to finish it before permanently attaching the second floor so I wouldn't have to work upside down.

Since I had added a piece of plywood to extend the front porch forward, I had two different levels on the porch soffit.  I glued thin sheets of balsa wood to even out the surface.

I then framed in the outer edge with 1/8" x 1/8" strip wood.

Using 1/16" x 5/16" bass wood, I cut pieces to cover the soffit.

I numbered the pieces on the back as I went along just in case things got knocked apart before I had the chance to glue them in place.

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Before finishing, I placed the second floor onto the house structure to make sure it fit properly.  It did.  Hurray!  :]

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I had originally planned to paint it white, but I think it looks awesome as is.  I'll paint the nosing and porch posts and rails white, but the soffit itself will be sealed to keep the natural look of the wood.