A new type of locomotive kit?

I have often wondered over the past couple of years whether anyone in the US would ever offer another steam locomotive kit.  Since Bowser and MDC dropped their product lines, the only source has been Ebay, which seems to be circulating a lot of the unbuilt kits.  Prices have seemed to decline over time, so I wasn't optimistic, in spite of the potential for interesting novelties that's inherent in 3D printing.  Eightwheeler Models announced a Civil War 4-4-0 kit in 2011, but it hasn't yet materialized. 

But now a couple of the bright creative lights behind the Yahoo Early Rail group have come up with something that uses not just new technologies, but a new marketing model.  The team of Gerry Dykstra, Al Mueller, and John Ott have put together a near-kit - a set of 3D printed pieces that can be used (with John's beautiful decals) to customize a Mantua General 4-4-0 (kit or RTR) into one of two Civil War-era engines - either the USMRR's "Lt. Gen. Grant" or the famous Western & Atlantic "Yonah."  Pictures are here.  Links to more detailed description at the Early Rail group, including Al's email address, are here. 

To do this, they are marketing the detail parts through Shapeways, available here.  Guidebooks for the Grant and the Yonah are sold separately, through a print-on-demand site.  You can contact Al Mueller directly for crosshead guides and for a set of John Ott's beautiful decals (his site gives you an excellent indication of his skills, his sense of humor, and his imagination).  For those who are interested in a third option, Al has been experimenting with the possibilities of this for some time, and his book on tweaking out a Mantua General is also available as a print on demand book, here. 

They aren't doing this for the money - obviously - but it's intriguing to see how they have cleverly leveraged other people's business models to create an appealing-looking kit with minimal requirement for the investments that have in the past made this such a tricky business: no need for dies, molds, or a massive initial inventory investment that takes a lifetime to sell off.  I hope they succeed - and I hope their success encourages others.