Tim; I love the design! It looks both sophisticated and timeless, a modern adaptation of a vintage design. That being said, I gotta admit, the rollerball just ain't doin it for me. That thing practically screams 18k gold nib from the outside, and the rb section just seems like a letdown when you open it. Not to mention, I would bet my last bottle of CA that if you plan to sell it, you could add $100 to the price by adding the fp section, and probably another $100 to add the 18k nib as an option. Heck, you could throw in the RB section and refill as a freebie.
For a platinum plated kit, I think the only option to get a FP section is to buy another kit though. I just don't know how a black and gold section would look with the white body. Might be super sharp, might just look plain wrong. I have one of each, and would be willing to ship them to you and let you try them, look them over, write with them for bit and see which one you like, and we could work out a trade from there. If interested, pm me.
As for the material, I must assume that it is what Ed and Dawn call "Casein" in their catalog (and sold out of before I could order any, Darnit!) But that being said, I would love for one of them to jump in here and clarify what exactly it is. A quick web search reveals that "casein" is, as expected, the protein in milk. No mention of it's naturally occurring in pen blank form. A little more searching shows that a product called Galalith (Erinoid in the United Kingdom) was made from milk protein, and widely used as an ivory substitute at the turn of the century, without celluloids unfortunate propensity to catch fire at the slightest opportunity. Inquiring minds want to know.
James