As I type this I am six miles away from Springfield's main manufacturing plant and headquarters, in Geneseo, Illinois. Illinois considers them "essential" so they have been in full operation these past couple of months, as has Rock River Arms. I worked for them in 1990 and 91, before going off with Les Baer. At the time they were getting their 1911 frames from Imbel, partially finished. They were imported without the frame rails cut and un -numbered. I was told that this was because they were not considered by the gov. as a "firearm" until the rails were machined and the frame numbered. This got rid of a lot of hassle as they weren't importing guns, just unfinished parts.
Don't know if all that was true, but it is what I was told. Don't know where they get their 1911 stuff today but wouldn't be surprised if they make their own. They certainly have a big enough facility.