7.62x25mm Tokarev pre-WWII headstamps?

Is there a checklist of 7.62x25mm Tokarev cartridges made before WWII?

The checklist I have from John C. and others seem to start with dates around 1942. Surely there was production long before this?

AKMS

The first documented Tokarev headstamps are from 1942. Prior to that they were unheadstamped and the 16-round packets were dated.