reduce your photos by amending the pixels to 600 x 400. That should leave the detail fine but allow you to get within 125 kb for posting.
It is I would say definitely contemporary - last 20 years or so perhaps younger.
difficult to tell but no, I'd say you can't age this one based on the pontil mark. Studios did leave them unpolished although I would have thought on a cameo, that the mark would have been eradicated somehow.
Cameo work comes out of a few studios/,makers, not many do it. It's specialised, takes time and costs money.
There is also work that comes out of Japan as well as the countries which more easily come to mind such as Australia, GB, USA etc. and probably many others as well. But as far as I know only a few studios/makers specialise in it.
The only sticking point is the pontil mark because it would normally be finished flat or finished somehow as far as I have seen. But I have seen blown studio glass finished like that. It does look as though it has been polished but I think the scar where the pontil rod was broken off was too deep to grind the pontil mark any more without damaging the glass piece.
It's a lovely bottle.
m