Lithgow 1916?

[Steve H. in N.Y.]

Did you check out this article yet?

1917/1945 No.1 MkIII* H.T. Sniper Rifle (Short Bracket)

No idea what the going rate is but I know they ain't cheap. Going by the serial number, this rifle was converted to sniper spec in January 1945 so I guess there's not much question of it's authenticity.