I have seen a few Leesons listed on various sites. They are beautiful guns and appear to be very high quality. Here are few I have found.

A beautiful bar-in-wood 20bore hammer gun from Briley's
http://www.youtube.com/watch?v=w7sEFpwgijs

A sweet little 28bore boxlock-ejector. Would make a great little quail gun. Lots a good photos on this one.
http://www.gun-vault.com/leeson28.htm

Gorgeous 20bore backaction, toplever hammer gun.
http://www.ospreyarms.com/category_details.php?i=4&id=181

A very nice 20bore boxlock ejector.
http://www.gun-vault.com/leeson20new.htm

And lastly, another nice 20b BLE... great bird gun. Well... they all are!!!!
http://www.gun-vault.com/leeson20htm.htm


Adam