Wayne - These Pics of an identical sight fitted to my 1875 WR Monkeytail may just help

The 1500 yard top notch is rather optimistic!!

Unfortunately yours appears to have broken across the hinge, although a good gunsmith can do wonders

Cordite - your wood rod may be more original than my metal one. without the extension (may not have been needed on yours), the rod is not long enough to push out a stuck case

Tony