Here you can see some fine internal stress cracks. At this point in time (early 1930's) Hemingray had the annealing process all automated, and you would never really see any internal stress cracks. But if you heated it up yourself too quickly and/or cooled it too quickly, this can happen...

I remember buying the altered one in 1990, and the owner said he had it for 20 years or more... His time frame could be off a bit, but we know they were playing around with carnival coatings in the early 1970's at the latest.

If you haven't figured it out now, the left one is likely real, and the right one a fake for sure...