Following up on a question I opened up earlier (Joining more objects breaks fill), I have a mesh produced by repeated application of boolean modifier 'difference'. (This represents a Type VII submarine deck with sea water cut-outs to be 3D printed in due course.)
In a few cases, however, I was not able to get the booleans to work despite moving the modifier objects slightly, re-editing them, applying various suggestions found on the internet, etc. Fortunately, the number of problems is small (4 items) in comparison with the whole project (several hundred), and in each case I have a similar slot nearby which I can theoretically reproduce if I can figure out how.
I am wondering about doing these last four manually by copying and pasting in existing sections of the wireframe (for example). I am able to select a section of wireframe, move it to the right place, and separate it as a separate object (if need be), but I'm not sure how to paste it in so that it creates the proper intersection points so that I can cut out top and bottom faces and end up with holes going all the way through (as well clean topology).
There may of course be other, better, or less 'manual' ways to do this...