Looking to buy a Danish 1867/96 Rolling Block

[butlersrangers]

'Patrick' - I no longer have a Danish R-B to directly refer to. But, IIRC, the 'Volley' graduations or distances are simply visible on the 'Leaf', when it is in the vertical position.

The rear 'Volley' sight is the off-set lobe on the elevation slide, that extends to the left of the leaf.

The front 'Volley' sight is the 'flanged-screw' head, that projects from the left of the middle barrel-band.

I have Geoge Layman's earlier work, "The Military Remington Rolling Block Rifle", 3rd edition. On page 35, Layman mentions about the M1867: " ... a longer than usual ladder-type rear sight with a secondary sight notch on the left side used for long-range fire". (So, George Layman is aware of this feature).

I've borrowed and edited two of the OP's pictures:
Attachment 79867Attachment 79868