I think the stars on top of the caps on the M. Fonteius coin are what associates them with the Dioscuri, not the caps themselves.
I'm sorry for asking as I just noticed that on member Ajex's Cordius Rufus. coin there they are wearing the exact caps...
Congrats Donna! I hope one day you get a Quadrigatus with the Dioscuri so we can both have the same awesome coin. It’s still my only Dioscuri coin .