The first denarius is Crawford 199/1a. This is the coin, known by Crawford. Interesting is here the inscription on the reverse : SAR under the two horses, the S beginning next the leg.
The second denarius is the same reference number, but the reverse is different : the inscription SAR is more at right and before there is a C partially erased. The moneyer is perhaps Sextus Atilius Saranus (Serranus), consul in BC 136.
Probably a mistake of a careful engraver who was used to engrave C.SCR, as the third denarius, Crawford 201/1. The moneyer here is C. Scribonius.
From this second denarius are only 5 examples known, four cited in the work of Pierlugi Debernardi, 'Varianti di conio utili per la catalogazione dei denari repubblicani' and all four from the same die, this coin = d item.
This variant is unknown to Crawford, because not in museum collections of hoards. He dates the Atilius coin in BC 155 and the Scribonius coin a year later, in BC 154. Maybe we have to change the date of the two coins. albert
ps : I had problems with the images, is there a manual ?