The Field patent of 1877 covered both the tilting block (Martini style) and the true falling block designs.
You also mention Kipplauf.
What action type are you looking to duplicate?
I agree with bouldersmith, those castings need a ton of work to finish to any standard.
You may consider simply buying a Field actioned gun or maybe building a Kipplauf on a single barrel trap gun - a project I myself plan as my first build attempt.
The beauty of buying an existing gun is that so much of a gun's value is placed in the barrel. There are a lot of great actions with poor barrels around at good prices.
Of course, if it is the challenge of the build you are after, that's understandable too.