the snow is made with "renoband "from "knauf" look for that on Google and i hope you know it.. it's a lightweight plaster ,and if you ope the bucket you will see modelsnow hahahaha
Even in the close-up looks very convincing! Nicely done!
People use for snow whatever they can find, mostly baking soda. But I was told it is getting yellow over a time. Apparently there is some company that sell white marble dust. May be too large for 72nd scale but in 1/35 looks real enough. I have yet to try to build something with snow.