Gareth,
It shouldn't be a new piece as they stopped making them in 1986. I've got Nr 526, with a very similar mesh pattern, which is a littel bit of an oddity.
According to Ruding's chapter on Orrefors coding, 486 was designed in 1969.
She writes, "Starting in 1960 kraka was brought into series production, though unique pieces were made, too. Certain model numbers were produced in long series from 1960 until 1986. They are marked with P or PU and the serial number, and sometimes with article number 9414 before the serial number."
She lists the models that were produced in long series, and 486 isn't one of them. From the absence of the "P" I would say yours is a 1969 version. I can't explain the other numbers.
I seem to remember another thread that covered much the same ground as this one. Perhaps it has more info.
Beautiful piece.
David
PS I found the thread but it doesn't add much.
http://www.glassmessages.com/index.php/topic,40305.0.html