C&O K-4 2-8-4 and H-6 2-6-6-2 (cont).
Clear coat, assembly.
White walls: I sanded the sides of the paint pen, first, using some 220 grit to get a fine point for applying the paint to the running boards and all wheels rims.
Sides of frame gets the paint scraped away for electrical conductivity. Many of the frames have small lugs sticking out to hold the driver springs.
The driver's journals will, usually, have a recess for the other side of the spring.
It took me about an hour to assemble the valve assembly. I didn't put the parts in their respective order and had to, logically, figure out where the parts went plus what size screws as I had to remove 4 screws from this side when it was disassembled. All back together and no binds 
New can motor siliconed to frame. Small piece of metal rod between motor and gear for stability.
Easier to mask than try to clean paint out of those holes! Same with bolster holes.
All the hard parts are together for both engines. LED's glued in.
Getting 'down there' with only 11 more engines to paint. Been doing it since the mid 70's so only 45 plus years to complete this project!
Not counting the 7 logging engines yet! Gives me something to do during the winter!
