Postumus, AV aureus, Cologne, 6.32 g. 

IMP C POSTVMVS PF AVG, laureate, draped and cuirassed bust right.
AETERNITAS AVG, Three radiate and draped busts of Sol of 
which one is facing between the other two facing him.

RIC 18d; Schulte 18; Calicó 3709; DeWitte 11 (describing the 
reverse as the radiate head of his wife facing, between the 
radiate heads of his son and daughter). 

Extremely rare, possibly the second specimen known of this 
variety and the fifth of this type. 

With permission of Numismatica Ars Classica, Oct 2009
Estimate: 80,000 Swiss Francs.