thanks Roy - lead glass from that period should have a distinctive greyish hue - I don't believe it should appear bright as with C20 lead crystal - try comparing the colour with anything you might have from the Georgian period - you should see the difference.
When you think of the working life of a 150 - 200 year old inkwell, my opinion is that it wouldn't be looking quite this good - and anything with sharp corners/edges is going to suffer, and you'd expect to see some edge wear/damage. It's true about base wear though, so that's not necessarily a reliable indicator, but I'm a big fan of wear, and get worried if I can't find what I think I should be seeing.
I'm just a tad worried that, as you say, it's too 'near perfect'.
I had a notion that flat bases were possibly an indication of Continental manufacture - and this might tie in with the colour i.e. meaning that this could well be soda glass. I assume there wasn't any residue of dried ink - and is that a separate liner I can see? There is a considerable amount of work gone into this piece - although possibly it may not have the age we first thought.
I'd hoped others might comment - my thoughts could be very wrong.