A bit of porn. The 42 " barrel is by Numrich. The Tingle lock is usually seen on his shotguns only - but the guy at the shop where I bought it said Tingle would make most anything the customer wanted. At any rate - I haven't seen any other Tingle "Mule Ear" rifles. 100% sure firing - and the set trigger is adjusted down to about an ounce. Very accurate little gun - I usually load 25 grains of 3F behind a .310 ball and a .010 greased patch. Bought it back in 1970 (about) and I have no idea what it's worth - but it's not for sale anyway.
http://s338.photobucket.com/albums/n431/jim4065/