It is important to recognise that the vast majority of styles and variations may have never been documented at all, with every little remote village possibly having some knowledge passed down from generation to generation. The Shaolin Temple merely happened to be a gathering place with a strong enough tradition of formally collecting this type of knowledge. Therefore there may be a lot less meaning to "Shaolin style" than many people assume. There is a great condensed history in The Shaolin Workout although I'm sure many better references are available.
I believe that a lot of work was done to formally document Chinese martial arts by the Central Chinese Martial Art Institute   in the early 20th century. However with the Cultural Revolution outlawing the practice of martial arts, many of the masters either fled China or stopped practicing openly. Some established schools in Taiwan and Hong Kong but many are now old and very traditional in their teaching approach in that they'll only teach one student, if they can even find one they consider worthy; most are also weary of foreigners. As you can imagine, this is a serious threat and possibly countless forms and sub-styles have been lost already.
Back to establishing a link between specific schools and the temple, it is best to ask for the particular school's lineage of masters and try match that up with known historical figures.
The opinion of my school's master is that what is practiced at Shaolin nowadays is a much more acrobatic form of Wushu acceptable to the current Communist government, and the Shaolin area with its countless "Shaolin" schools is merely exploiting the name for commercial gain. (I am merely relaying other visitors' impressions here, take it for what it's worth.) This view was reinforced when the traveling Shaolin Monks show visited our school in 2010. For one, the troupe were amazed at some of the forms - particularly weapons forms - that they witnessed in a western school. What I'm getting at here is that an official "Shaolin stamp of approval" may not mean a whole lot today. By the same token, it sounds like the Communist Party has also realised that they've made a mistake in wiping out a huge chunk of history and are actively working to restore some of that in the name of national pride. Just bear in mind that their vision of Wushu may no longer fit the traditional definition of martial arts. (Think WTF Taekwon-Do.)
The "real Shaolin" styles are probably lurking in a myriad tiny independent schools in the most unexpected places, and proving a formal connection is not necessarily all that important.