I would be interested in opinions on whether the first coin looks official, as it combines the mintmark of Lyons 246 (dot before PLG) and Lyons 256 (dot in wreath before PLG). It looks pretty good to me, but they often do!. Also attached are two photos of the normal 246 (one with normal shield and one with sideways shield), followed by a photos of an example of 256.
Weight and diameter of the unlisted mintmark coin is 2.15 g / 16 mm
It's interesting...it doesn't look definitely unofficial; but many unofficial coins look pretty good. The robes of Victory are usually longer, going all the way down to the feet. Her face is also pretty crude, with a large round eye. The end of the sceptre closest to her feet is larger and rounder than usual. The shields are typically taller. None of these things mean it is unofficial though. Maybe it is 256 with dot in crescent and just an odd bit of engraving. The engraver may have started too far to the left. I have had a few coins with odd dots. So, I am just not sure! :D
Thanks Victor, exactly my dilemma! - I think it will have to stay in the uncertain basket unless another example comes along, especially if in one of the other types, i.e. Gloria Exercises or Urbs Roma