Mike - I have some upcoming projects I'm pretty excited about. Not sure which I will do first, or when I will be able to get to it, but I'll start a thread with ongoing progress for each of those as well.
Dave - Thanks! My plan is to go with fake water this time around. If I ever build a super "dream" layout, I may go the real water route 
___________________
Alright, I was able to make a little but more progress. I disassembled the mill & removed the incandescent bulbs. I plan to re-use the existing wiring and the lower level mounting points when I install the LED lights and the motor.
I decided it would be easier to do the "mortar lines" while the mill was unassembled after all, so went ahead and did that first. Given the deep grooves in the façade, I used pre-mixed drywall spackle. The end result came out much improving the stone look. Still have a little clean-up work to do around the windows & need to do a final wipe-down:
In the pic above, the wheel is actually mounted to the building for the first time. I drilled the hole for the motor and test fit it in the available space. The motor fit better than I had any right to expect, neatly sliding in to place above one of the cross beams. I did have to remove one of the lower level mounting posts, but there are plenty of others:
Here's what the axle looks like, protruding from the building. I will paint the axle black so it blends better.. This is also a pretty good shot of the brick work... rubbing off some of the excess spackle had the unintended positive side effect of rubbing off some paint & making the stones look more convincing. No mistakes, just happy accidents:
Here's how the motor sits in the upper "section" of building:
I glued in some thin prices of wood so that I can mount the motor with small screws. I may also use a dab of glue (but little enough that I can torque it free if a swap is needed):
As far as the roof, I took Dave's suggestion and eliminated some of the smokestacks. Ultimately, I removed 3 sets of stacks... which still leaves 3 remaining. The ones I removed will likely be useful in bashing other projects, so this is a win-win. I covered the holes with pieces of thin scale aluminum sheeting I had on hand & glued them in to place. Not sure if I will paint them rust red to match the roof or just rust & weather them a bit. Either way, I'm also extremely happy with how well these "patches" fit in to the original roof and look like repairs. IMO, imperfections give buildings character:
I had planned just to do a partial interior by the loading dock, but this thing has enough open space inside that I'm considering doing a more complete (albeit basic) interior. I'd have to replace the window glass with a more transparent plastic as well, but may be worth the effort...
