thats a beauty!
http://auctions.holtsauctioneers.com/asp...768&image=6

"ALEXR. HENRY
AN EXCEPTIONALLY RARE 20/.577 ALEXANDER HENRY BLACK POWDER EXPRESS ROTARY-UNDERLEVER DOUBLE HAMMER RIFLE, serial no. 6123,
28in. black powder only fine damascus barrels with Henry patent rifling, Adams & Tait no. 5046/7, partially file cut rib engraved 'ALEXR. HENRY. EDINBURGH AND LONDON', open sights with bone inlay sighting triangle and folding leaf sight with white metal inlaid sight line and marked for 200 yds, ramped bead fore-sight, treble-grip action with Jones patent rotary underlever, carved percussion fences, rebounding back-action locks with bolted dolphin hammers, fine border and acanthus scroll engraving, retaining traces of colour-hardening, 14 3/4in. figured pistolgrip stock with steel pistolgrip-cap, sling eyes and including 1 1/8in. rubber recoil pad, fore-end with grip-catch release lever, weight 10lb. 11oz., in its brass-cornered oak and leather case with some reloading equipment, including serial numbered bullet mould and plug

Provenance: The makers have kindly confirmed that the rifle was completed on the 28th January 1888 as a 2nd Quality rifle as part of a batch going to Manton & Co.

Other Notes: The 20/.577 cartridge was developed by Alexander Henry and the first rifle produced in this calibre was in 1883. Donald Dallas has undertaken extensive research for his new book 'Alexander Henry, Rifle Maker' and his studies of the Henry Dimensions Book makes reference to just 33 examples, both hammer and hammerless. "