Question on the Generic build...

Hi Guys. I am in the middle of my Generic Benroy build and I have a few questions.
I don't see any details on what materials to use for the top. I plan on skinning with Uni255 and thinking about using 1/8" Luan. COMMENTS...
Also, how and where should I join/mate the three top pieces? (I am 58.5 wide).
How should I finish / join it to the frame on top of the tongue?
How can I finish the lower rear area below the hatch? I really like that clean white look mike has given it.
I see on the plans that Mike has an outside "porch" light on. I would really like to put one on each side, but I can't think of how to hide the wiring on the inside. (3/4 Birch walls..) THOUGHTS...
One last question, on the Uni255, Tom Swenson mentions how it gathers lots of dust/dirt. Is it really that bad? (I really like the thought of using it over alum or filon).
I don't see any details on what materials to use for the top. I plan on skinning with Uni255 and thinking about using 1/8" Luan. COMMENTS...
Also, how and where should I join/mate the three top pieces? (I am 58.5 wide).
How should I finish / join it to the frame on top of the tongue?
How can I finish the lower rear area below the hatch? I really like that clean white look mike has given it.
I see on the plans that Mike has an outside "porch" light on. I would really like to put one on each side, but I can't think of how to hide the wiring on the inside. (3/4 Birch walls..) THOUGHTS...
One last question, on the Uni255, Tom Swenson mentions how it gathers lots of dust/dirt. Is it really that bad? (I really like the thought of using it over alum or filon).