Stan;
I missed that one, description of both barrels read like shotguns not rifles. Lefever did make some double rifles, but all I have ever heard of were in regular rifle calibers of the day, have never seen a reference to a rifled barrel in a shotgun size. Likewise I do not see any signs of sights on these barrels.
Also if I didn't get the barrels mixed up I believe it is this set of cut barrels which has a 2nd SN stamped @, 31,224.
As best as I can make out the patent dates it has a last date of '87, does not carry the 1907 date which one would expect on a gun built in 1917.