First of all, the winter camouflage wasn’t applied at the factory… Winter camouflage is time and regional-specific . The Germans used a water-soluable paint, similar to tempera paint, that was applied in the field by any means available. Depending on the Staffelfuhrer’s directive, the pilot’s personal taste, and the crewchief’s time, they were done meticulously, hastily, or somewhere in the middle… The winter camouflage paint was removed by washing the aicraft with soap & water and rags, mops, & brooms.
Maskings over the insignias and stencils were fairly common (The Germans, and especially the Luftwaffe, had a knack for camouflaging their aircraft for every little condition) during the application, but it wasn’t always the case, with some crewchiefs prefering to “freehand” the camo and just “block” around sencils, leaving the base color intact under the area of the lettering. As SF pointed out, sometimes several methods were used at the same time. Also, the amount of paint applied would be dependant on the supply, the local surroundings (Overall-white vs. blotched), and the type of aircraft it was being applied to.
Keep in mind that the aircraft camo is not, like many believe, to hide it from observation in the air by other pilots, but rather to hide it on the ground, break up it’s silhouette (disguising it’s type) and to fool others as to it’s true attitude (A great example of this practice is on Candadian F-18s that have a “false canopy” painted on the undersinde directly below the real cockpit, complete with a whte-blob “pilot’s helmet”).
I think most modelers prefer to do the “meticulous” white-wash paint (with some fading and wear) simply because it looks better than brush-applied, cross-hatched paint job, cheifly due to the fact that others (especially contest judges) will think their work is sub-standard because the paint was brushed rather than airbrushed, regardless of how historically accurate the portrayal is…
There was a great diorama someone did a few months ago (although I can’t remember who did it) in the Diorama Forum of a ground crew removing the white camo from a Bf 109… It was complete with half the white camo off, hoses with water running, buckets and mops, and a couple puddles of white-tinted “water” on the ground under it…
So the bottom line is research, research, research… Then go ahead and do it your way anyway, lol…