Hmm.  Before the Bessemer process, steel was made by the crucible method, which is a very time consuming process, that of heating to a molten state, back in the early days, meaning weeks.  Iron hammered is not really steel, but wrought iron.  Pure iron is a rather crap material, it may be hard, difficult to achieve, and it's primary quality is brittle.

Surface appearance for Iron or steel can be difficult to discern, there are so many different types or alloys that steel can be made with almost any properties you want.  Trying to discern between one and another on appearance, forget it.  Hammered steels will have a different appearance depending on what process is used, however a sword is usually hammered thin, doubled over, hammered to weld the two, repeat the process until you have the required number of laminations to give the desired strength.  This will give the different patterns.  The laminating process also welds the laminations together, in effect,many layers to give it strength and some flexibility.  Where these layers have been worked or polished will show in the surface giving the visible patterns.

As far as the patterns, there will be no such thing as two with identical patterns, or even similar, it's the result of the smith doing the work. Modern steel or iron, there is no guesswork, the appearance of the finished metal will depend more on the desired qualities of the material and the methods used.  I have made for my own use, cast iron flats, with a ground finish that until it is exposed to moisture will rival the finish achieved with 4140 HT, which is a prehardened chrome-moly steel.  I have also ground and polished 1018 and 1020 steels, which will give an appearance closer to gray iron than a steel. 

I would say, Earl, find something that pleases your eye and use that.  Nobody can confront you with "That doesn't look authentic", because there are so many variations, the task would be to prove it isn't authentic. 44 years of metalworking, I do have some idea what different steels, irons and alloys look like, ancient or modern.

Doric.

The "I" in Doric is Silent.