I replaced the bulbs in one of the C&O passenger cars with LED bulbs from Town&Country Hobbies. I elected to use 'warm white'. Here's a few pics comparing 2 cars, one with original incandescent and the other with LEDs. I like the lower light LEDs but you'll notice they do not adequately light the entire car. I'm on the fence whether to outfit the remaining 5 passenger cars with the LED bulbs. Looks like LED strip lighting in the cars may be the way to go if I want uniform lighting. On the other hand swapping bulbs is whole lot easier and cheaper and meets my goal of reducing power draw.
"It's always something."
LED:
Incandescent:
Lashed up: Incandescent then LED