Hi mike, yup I fixed it using MoI - first I had to figure out which particular faces were the ones that the edges belong to, I did that by first hiding all the other objects going down the middle area to get them out of the way, then select the main object and run Edit > Separate on it to break it into individual surfaces. Then clear the selection. Then I did a window select on the sticking out edge, starting on the right and dragging towards the left (the window outline will show dashed which means anything crossing it at all will be targeted for selection. The other direction starting left and dragging towards the right only captures things completely contained within the window). After grabbing the errant edge with a window select the edges of the object that gets selected will do a quick flash on screen, by observing that flash and also zooming around and looking at what is then yellow after the selection was done I could tell it was the inside vertical faces that were messed up.

So now that the pieces are identified I undid the separation, then since those faces are planar it's pretty easy to rebuild them, just select them, delete them, there are now 2 planar openings in the object and those can be sealed off by selecting the object and running Construct > Planar.

In other cases when the openings are not planar it can be somewhat more tricky, that involves doing an "untrim" where you remove the current messed up trimming boundary to recover the full underlying surface, and then using Edit > Trim to retrim it.

There's some information on "untrim" here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=444.4

And there's more detailed information on this kind of repair process in the object repair tutorial here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

Hope that helps!

Thanks, - Michael