To resize, manipulate, etc., I recommend using Sketch Picture.
However, the PDF will need to be an image file, I believe.
Look up "PDF2IMG". This utility "prints" a PDF to an image file usable with Sketch Picture.
EDIT: You can also use Windows Snipping Toll (or similar) to take a clip of it and save that as an image file.
More control than with PDF2IMG.
When I print the result (of inserted PDF) to PDF, the graphic looks like an icon.
Broken feature, or functionality that's really hard to use?
Yeah, I will export these from AI to PNG and insert them as pictures.
Of course, the scaling seems to be completely berserk there also. I will keep trying - this must be possible.
DWG worked on one, but the other is fighting me. Arrgh.
It just seems wrong to need to convert vector to raster for use in a vector /model/solids application!
I exported as DXF from Adobe Illustrator and used SW's Insert DWG/DXF.
The terminology and units between AI and SW still confuses me, but I was able to get them in and they look ok.
I suppose the picture import could have worked too, but I kept getting tiny images that still thought they were 5x2 inches.
I did not see the "sketch Picture" feature, but when I zoomed to the tiny pictures, they were not as clear as they should have been for the stated pixel resolution. Dragging them bigger did not seem to help either.
So DWG/DXF is the best solution so far.