I wouldnt worry too much about skin bumping. My own theory is that they will bump either really badly made rehash skins that were skins from the origional p51 that are completely innacurate or done with such low detail and minimal color variation that would make them stand out against just about any more recent skin that has moderately good colors and details.
or they could go after the cloners. theres a few skins for some planes that could have 6 or 7 slots for the same skin thats been altered in ways that are not visible from the cockpit and just a bit of weathering or nose art is different. I don't see a problem with doing a clone here and there as long as its unique enough to stand apart from its origional especially if its for a plane with no skins and a single skinner is trying to add a lot of variety in markings with just one skin as a stopgap till more unique work can be done by the skinner to their existing work if they so desire or more skinners add more skins to the plane and eventually decrease the number of cloned skin repeats.
but i think its best as waffle said a while back to do 1 skin for a certain plane and move on. I think revisiting a plane and doing another skin for it or finishing a problem skin that had issues that relegated it to the scrap pile till being sorted out has good results in that it will make each skin done by a single skinner of higher quality than the previous skin for the same plane simply by the time between skins and other skinning projects between them as well.
anyways...
I am starting my b25 default skin research tomorrow with a trip to the Museum nearby (at the inlaws still hundreds of miles from home) which dosnt have a b25 but has a very good reference library hopefully containing some great plan views of the b25.
I have some pretty damn good b25 plan views with rivet and panel detail at home. but if anyone has some truely unique drawings of the b25 with good rivet and panel detail or even really good pics showing such detail please share by PM'ing me or posting in the custom skins forum
like guppy said I love dtails and the more I can find about the origional plane the more I can accurately add to the skin