Denarius, type 4, var 4

Obverse legend
Reverse legend

Rx F (the letters R, x and F under a tilde, a cross between the letters R and F, a horizontal line below the cross; one globule in the center (to the left of the line), three globules aligned vertically to the left of the letter, one globule to the right x and another to the right of the letter F). 

MPIPI (the letters M, P, I, P and I under a cross, an ax below the letters).

One copy preserved at Münzkabinett der Staatlichen Museen of Berlin, link to the page of their website showing the photo of the coin:

G F XF 40 AU 58 MS 63 MS 65
1 ? ? ? ? ? ?

Seems never to have gone on sale.