Hi Joe,

I hope my model wasn't confusing...I drew it by eye before you posted your 3dm model, so mine is a rather simplified version
in comparison.

I did the whole thing all at once as a 2 rail sweep, but because the long side of your top surface has a shape
that is uniquely particular to both sides of that surface along it's length, you might get more predictable results by sweeping the surfaces separately,
as you have done....if you swept the top surface first and then used the edge curve of the top surface as one of the drive rails of the side
surface, the two surfaces will join without gaps.. (does that make any sense)?


Michael explained it much more clearly that I am...:-) , using commonly shared drive curves in a sweep will better insure that the resulting surfaces
join up into a closed polysurface without any gaps.



-Jesse