Hello Dragonmaster
This series of medals is extemely scarce. Strangely, no named specimen seems to have come to light.
Could well have never been awarded, possibly a trial striking. Besides Cussonneau's lovely set, I have one and very few others are known.
You are right to think that your specimen is the "bronze level". In fact, all medals known to date seem to be struck in bronze with a coating of silver or gold according to the level intended to be honored.
To my knowledge, no formal decree of creation has emerged. On the other hand, I am not sure it has been much researched.
Best regards
Vétéran