Hello - you can
FitSrf at say .001 to simplify but you’ll need to re-intersect everything - it will be messy, it would be better to go back to the originals. So, for now, let’s try to fix the edges well enough to print…
@gabbserrau -I’ll send you a closed object via our upload site…but, for the future, was not a good approach - Rebuild has some good uses but this was not one of them.
Another thing, your object is small - a fraction of a millimeter overall - so if you really want to make an object that tiny you need to work at much smaller tolerances - see