Thank you, TIG. There was a small problematic part I could not handle, so I copied it from your cleaned-up version. And you're right... sometimes I spend too much time looking for a script to automate a task or a 3d warehouse model that suits my needs, when I could have done it manually in half the time.
But I highly recommend "extend close lines". It really saved me time with this drawing.
And Todd, thank you for checking out this odd case. I'll continue in the Smustard forum.