Brionne Lever Handles 15-60102,  available in lock, latch, 92mm Euro or bathroom version.
Back Plate 300 x 40mm

available in Patine Rust or black
Patine – This has a pewter patine (old iron colour Dull Pewter Grey) and has anti corrosive properties which makes it ideal for external use.

Code 15-60102

Sold in pairs complete with fixings and spindle
Unsprung ~ Heavy sprung locks or latches required: see links beolw
http://www.phg-uk.com/product/from-the-anvil-anvil-tubular-mortice-latch-heavy-duty-18299-2-5-inch-3-inch-4-inch-5-inch/
http://www.phg-uk.com/product/from-the-anvil-heavy-duty-sash-lock-stainless-steel-18238h-2-5-inch-18239h-3-inch/

(please check for availability if needed urgently as these can take 4 to 6 weeks if not in the uk )