I've used John Downing's independent built to verify the fixture of loading 3DS models into GMAT. Hughes/Downing were working on merging John's fixtures so it can become part of the Nightly Build.
I'm assigning this ticket to you so you can use the attached 12 scripts to create GUI tests. Attached zip file contains 12 .3ds models that were tested. I have also committed these 12 .3ds models in our JAZZ repo (...\JAZZ\test\script\gmatdata\vehicle\models). Please update your repo to see these new models. You'll see 12 folders for 12 .3ds models.
In the attached script, you'll only need to update GMAT DefaultSC.ModelFile field and give your own absolute or relative path where your .3ds models will be located.
When the GUI tests are complete, you can close this ticket and
GMT-4898 as well.