Dave - Never even thought of that. When I did that I received an error about UV issues. So I did a 3D->Generate UV, then 3D->Unify Scene for 3D Printing and was able to bring it into Prusa Slicer and am printing it now. I did try just the 3d->Unify Scene and it did not work, so the Generate UV was the key.
Thanks for the hint about importing the file back to Photoshop!