Watch List notes:

NERO, (A.D. 54-68 A.D.), AE as, (10.57 g), a very rare hybrid, probably from Lugdunum mint (BMC), obv. laureate head right, around, NERO CLAVDIVS CAESAR AVG..., rev. S C across, Neptune standing to left, (S.-, RIC, BMC 391 note [p.276] and Plate 48; 11 [the Walters example, our example similar to that illustrated and only known from the Walters Collection and it again was illustrated in Num. Chron. 1915 p.333 and Pl.XVI]). Dark brown-green patina, score mark on reverse, slightly off centred, good fine/nearly fine and excessively rare being probably the second known example.

Ex Noble Numismatics Auction Sale 79 (lot 3600).
Walters describing his example on p.333 of the Numismatic Chronicle of 1915 states "Apparently (an) unpublished coin of Nero.. an as with the reverse type of Neptune standing, similar in all respects to that on the coins of Agrippa, although the work is of a different and superior style.." [he then describes the coin] and further states; "This coin, although of the Agrippa type, is not a mule, as the work is of the time of Nero. It is also to be noted that Cohen quotes examples of two 'second brass' coins of Nero with altar reverses that like those of the Augustan type. These together with my coin appear to show a tendency at a certain period of Nero's reign to revive well-known types associated with the reign of Augustus."