Assuming that your model has not been cropped by a floating viewport,
you could make a block out of the paperspace entities, insert it into
scale it the inverse of the scale factor of the viewport, turn off any
that were frozen in the viewport, and now your should have something that
look like your paperspace version (positioning issues aside). HOWEVER it
will not be the same size in units.
If you need it to be the same size, you will have to scale the whole thing
the scale factor of the viewport. This may, or may not be smart.