Ausgustus Aureus
Obverse:
CAESAR.AUGUSTUS.DIVI.F.PATER.PATRIAE
Bare head of Augustus right.
Reverse:
C.L.CAESARES(in ex.)AUGUSTI.F.COS.DESIG.PRINC.IVVENT
Caius and Lucius standing, each holding spear and shield.
In field, simpulum left and lituus right.
R.I.C.350, C42, or 43.
Example of reverse pictured on plate 111 no.47 of vol. 1 of RIC (first edition).

It's a bit knocked about, and somewhat scuffed.
I bought it for AUD $750, personally off an employee who worked for Seaby's in London for many years, when I met up with him at the Sydney Opera House, way back in January 1992.
Has been in my collection since that time.