so it's 8 and 8 both of the same rarity it's normal for coins of the same issue.
here is my last adding
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IMP CAES M ANT GORDIANVS AVG radiate, draped and cuirassed bust right
seen from front
FIDES MILITVM Fides standing left holding standard and sceptre
compleetely unlisted even in Bland thesis
my 4th coin with this bust and the 3rd unique
this type of bust is actually known for those reverse
AEQVITAS AVG (3 coins London, and 2 private french collection)
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From
Thibaut Marchal's collection
CONCORDIA AVG (1 coin)
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from my own collection
FIDES MILITVM Fides seated (1 coin)
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from
Christophe Morand's collection
FIDES MILITVM fides debout (1 coin illustred before)
PAX AVGVSPP (1 coin probably a dubble struck)
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from my own collection
P M TR P II COS P P Mars (2 coins Lanz auction and private american collection)
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from Charley Rhodes's collection
PMTRPIICOSPP providentia (7 coins London, vienna, Bruxelles, 3 in private french collection and 1 in my own collection)
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from my own collection
so far I know 3 obverse dies for 15 coins known, unfortunately 1 picture is still missing in my database...
roger Bland's thesis only refer this bust for 2 types AEQVITAS (1 coin) and P M TR P II COS P P Providentia (3 coins) so within 20 years we have 4 times more coins and 3 times more types for this incredible bust!