I've been doing some sums, and it looks like I'd need to sell about eighty to a hundred copies of each of my models on Shapeways in order to pay myself a reasonable hourly rate for the amount of labour put in to designing the things.
Frankly, that's looking wildly unlikely. I don't think there are enough Interwar Nerds in the world, with enough discretionary income, to make this exercise in 3d-Printed Interwar Nerdery a financial success.
I could increase my own markup on the models, but frankly, 3d printing is already expensive enough to be a niche luxury market. I'm just hopeful that the cost of higher-resolution printing comes down to affordable levels within the reasonably near future.
Ah well, for the moment I'm enjoying the process of building these digital models, so I guess until that changes I'll just keep going. It's not like it's costing me anything but time, after all.