Its S/N 696, I believe. It has the auto retacting forward retaining clip on the mag body, so it has the said modification to the receiver.
Looked at nine rolling blocks, none of which had a proper replacement sight leaf (no 45-70's in the lot). Closest were the 43 Spanish but either face the wrong way or are mangled worse than mine, plus only graduated to 1100(meters?).
Will try and post pics eventually of this rifle and some later models! (missed out on the US Navy 1885- it sold in Ohio)
BTW but on a related topic- What's the difference between 45-70 and .450 Gatling? No info can I find on the latter.