Hi friends,
I'm from Germany and new in the forum.
Can't answer you questions, but will show another gun with Field System.
It is made by Holland Holland in 1892 for a certain Captain Hayes.
The weapon has a 70 cm long barrel, with a simple open sight two folding leaves. It is equipped with a 3 time magnification scope that has a mechanism to absorb recoil by a telescopic part.
Also you only have to estimate the distance, with a brass knob you sign up the distance and you have your point to hit.
The system is over and over with very fine scroll engraving, also the trigger guard, the long strap, the lever and the pistol grip.
There is a lot color case hardening remaining on the reciever, also nearly dark blue srews.
The wood is time darkenend, but nicely figured, the forehand ist used with a buffalo horn ending.
I got one original cartridge and the original loading recipe from Holland and Holland.

A German case maker built me 25 cases, Johannsen Reloading equipement took care of a reloading dies set.
Load is 60 grain n140 with paper wads .450 Bullets with 350 grs from woodleigh, to be used in blackpoder barrels, converted to nitro proof.

Its a lovely document of the good old times, that have been running away.

I will soon post some pictures.