I don't know how it is today but back a few years I was told by Holley almost all kits were made in Mexico by one company and packaged accordingly for the various vendors.
I just recently used a kit I got from Carbs Unlimited. It was a Tomco #5281. Seemed to be as good as any other carb kit I have used. The carb works great, not that there is a lot to an AFB.