Mark, thanks for adding the info about the differences in blade lengths and era.
If you're looking for separate MTL loads, it looks like they just announced a "Prop Blade 2-pack" and "Hub and Generator 4-pack". The prices look quite reasonable to me.
At these street prices, I could get 6 blades and 2 generators + hubs for $60 (enough for 2 windmills), quite a deal I think. The weathered 89' flats look interesting too.
http://blwnscale.com/mt-special-run-trainsets.htm#wind