A lot of you know I am a big-time railroad enthusiast - both the real thing and model railroads. I'm fussy when it comes to the model railroad, with a heavy emphasis on fine detail. I make a lot of the buildings from scratch, and almost all of the scenery. Some lay their own track with little spikes, but my model railroad is so large it would take me several lives to do that... I'm currently painting backdrops as part of the scenery. Good, creative hobby for my liesure time.
At any rate, a model railroad friend of mine found yet another definition of 'punk': Dry, spongy wood sometimes used as tinder when lighting a fire.
I've no idea whether punk was ever used to help start the fire in a steam locomotive or in the stove in a dining car.
Consider this the linguistics lesson for the day.....
Never stop learning new things....