Hello- the cad file download (ASX00039-cad-files.zip) does not contain a .step format file for the GIGA display shield.
Screenshot of where I acquired the zip file from ARDUINO website:
Thanks if anybody can assist,
-FB
Hi @fb2501. The file is available, but isn't listed on the documentation web page due to a bug in the documentation system. You can get the file from the Arduino documentation source code repository, here:
Click the downward pointing arrow icon ("Download raw file") at the right side of the toolbar to download the file:
Hello ptillisch, thank you for pointing out the step file.
I downloaded it and it opened up OK. I notice that some of the components float in space far from where they belong on the board.
In parallel, a coworker used the ARDUINO files from the link (red circle, red arrow) in my previous post to create a STEP file- he had the appropriate software to do that. In his file, the board components (mostly) show up on the board where you'd expect to find them.
If it's appropriate to do so, I'd be glad to post that file as a resource.
Thanks again for your help,
-FB
If you like, you can also submit a report of the problem to the Arduino documentation team.
You can do that by submitting a ticket via this contact form:
https://www.arduino.cc/en/contact-us
Or if you prefer, a GitHub issue to the bug tracker in the source repository:
You are welcome to do so. Thanks!
Hello, bug has been solved, now you can download the step files directly from:
https://docs.arduino.cc/hardware/giga-display-shield/
I also checked the STEP files, on my computer and using freecad as CAD program all seems in place, not floating components, so it could be CAD program related 
Regards
Is it me or are the mounting holes not showing in this STEP file?
They are not, which is the most important thing everyone needs