I am not aware of any repro tags.
There is a guy in Bismarck ND, Byron, that has a website. Google Dakota Connection. At one time he had stacks of used Carbs in his Garage, likely with tags. If you have a specific tag in mind he may have it. He sells a lot of parts at different shows. Usually very fair and reasonable. Not a lot of C-body specific parts, but has torn apart and documented many A and B body parts.
Also @Dana from Woodruff carbs may have some tags off some cores that are no longer usable.
I asked Dana first, but found my carb through Dakota Connection, and it had the tag on it still, so that was a bonus. Nice guy who's easy to deal with. He even brought to it my local show to save on shipping.