I think I that I have an AE4 of Valentinian II with Salus on the reverse. Do you agree/disagree? Can you attribute further, please? My confusion arises from me seeing ****NINVS AVG in the obverse legend which may be Antoninius Pius/Marcus Aurelius/Caracalla/Elagabalus/or even Saturninus? But I can't see that any of them have SALVS REIPUBLICAE on the reverse. (and a lighter image)
It will be one of the ones on the bottom row https://www.tesorillo.com/aes/_rev/index103i.htm I'll leave it to you to decide which one. After identifying enough of these you will be able to discern between 1st 2nd 3rd.... century coins just by looking at the coin and bust.
I am picking the first one. After you put me onto Tesorillo (in a previous post) I went there for this coin. That is how I came up with the Salus Reipublicae reference, and also the Valentinian II but I am finding it hard to read Valentinian into the obverse legend.
Here is a page of late Roman reverse types: http://augustuscoins.com/ed/ricix/ and who issued them, with examples. Yours is type 39, somewhat like this one on the "Type 39" page linked to that page:
@Valentinian Thank-you for that. With Tesorillo AND your reference my life should be a lot easier. I am off to get a coffee and to settle down to study it. Thank-you, again.