Thanks, Joseph!

Looks like I need to do some exploratory work this weekend and see what
I can discover about "C". I'm hoping the proper air space was
incorporated into the construction, but not counting on it.

Looking at my soffits: The soffit is wood (rough-sawn cedar). I'd like
to get a continuous vent in the whole length of the eave. Right now
there are maybe 6 vents along a 60 foot length of eave.

Wish me luck...

Matt