Parts I purchased:
1) 6VDC 45 RPM Pinky Finger Sized Gear Motor 1" Long x 15/32" x 3/8" (amazon).
2) Coaxial Power Jack (Radio Shack part number 274-1583).
3) 3.0 Vdc Power Supply (Radio Shack part number 273-315 with the "N" style plug 273-345, you get one free with the power supply).
Print all pieces as shown in "Assembly.skp". For "Chimney Front.stl", "Chimney Back.stl" and "Chimney Side.stl", I started the print in grey, paused the printer at 2.2 mm, changed color to red, then un-paused the printer. The grey color gives the appearance of mortar between the bricks. I then hand colored the ends of the protruding bricks with red (I used an indelible ink marker).
Test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on the colors you chose and your printer settings, more or less trimming, filing and/or sanding will be required.
Assemble as per "Assembly.skp".
Wiring is pretty straight forward, however you'll need soldering skills and equipment. Basically, solder a 6" red wire between the gear motor "plus" terminal and the coaxial power jack "Center" terminal, then solder a 6" black wire between the gear motor "minus" terminal and the coaxial power jack "Shield" terminal. Make sure the wires do not interfere with moving components.
Lubricate moving surfaces with light machine oil.
Comment if questions.
Hope you like it!