Thanks for the replies.
I was afraid i'd have to reconstruct the tears individually, as there are 200 of them!
Never mind. :(

Hello davetwo,

sometimes it helps, to import to an other CAD-Program (e.g. Freecad?, ...), look at the result and export from there. Or You try to get an other file-format from your supplier e.g. IGES or SAT.

Good luck!
Karsten