Please see the Nakaya website for size and weight measurements:
http://www.nakaya.org/esize.html.
For general information about Urushi lacquer, please consult these web pages:
http://www.nihon-kogeikai.com/TEBIKI-E/3.html and
http://www.urushi-kobo.com/process.html. A quote from the latter website:
"Well made urushiware lasts more than 100 years, possibly even another several thousand years."Learning as much about urushi as you can will enhance your appreciation of fine lacquer pens from Nakaya, Namiki, Danitrio etc, as the basic lacquerware process is the same.
In regard to "whether this lacquer will last" - well, under what circumstances? If you throw the pen onto the pavement, the lacquer will not last.

If you treat any pen in a nice, respectful manner, it will provide you many years of enjoyable use. I have urushi pens from the 1930's which are in excellent condition.
Also, a search of the forum will reveal much discussion about Nakaya pens!