Help Please, 4.55 gram Sev Alex Denarius ????

[Ken W2]

Please help with this coin.  Is bears a heavily doubled IMP SEV ALE-XAND AVG obv. legend and a IOVI CONSER-VATORI rev. with Jupiter with thunderbolt/scepter and the little SA to the lower left.  It measures 19.5 mm and weighs 4.55 grams.  I understand the Denarius of that era was around 2.5 grams.  This is not a radiate so I don't think it is an Antoninianus worth 2 Denarii and it does not appear to be one of the posthumous Ants of Sev Alex.

Also, note the red spots mostly to the left.  These are not raised encrustations but are within the metal and the color you see is flush with the surface. Any idea what that is?

Any help would be appreciated.

Ken     

[justinopolitanus]

By lead?

[djmacdo]

The picture is regrettably blurry--you might get better results just laying it on a scanner.  Does the coin have a reverse?  A look at both sides would help.