Small corrections to CAD file

Need to fix some minor issues on a CAD file. File is in Google Sketchup (can use <[login to view URL]> to import into autocad). 1) Need 5 sections fixed... close the existing gap 2) Need the corners fixed on the groves. Once that is done I need the model saved. Then... I need a box inserted inside the model (air) so I can shrink it and 3d print it (without having it solid). For the scale it's at I need that box 1.5" from the deepest groove. This should be minor work for anyone with basic cad exp. Output needs to be in sketchup (.SKP export tools floating on the internet), or .DAE or .3DS. I can import in any of those. If you use something other than SKP I'll have to check to make sure I import ok... it should work though. So I expect 2 files... one corrected and one corrected with the hollow box inside. ## Deliverables Pictures of fixes included along with CAD models.