Quick and Easy Questions (please read the OP)

[Amaterasu]

I recall that you could have two functionally identical weapons of a kind (two swords, two daggers, etc) as one move costing 300 OM, my question is could you also choose to use one independently from the other and still have them be one move?

And would that one move cost 600 anyway because of the two different "modes."

(I'm asking this because I'm working on a character from the Witcher series, where they reserve a silver sword for supernatural monsters and a steel one for more mundane threats. I realize that they'll be mechanically the same in the OV.)

So long as the difference is cosmetic only, you can go ham. If the sword's only difference is what metal it is made of (and possibly minimal differences that have no bearing on its combat efficiency, like how its guard is different), then you'd be fine with it costing 300 OM only.