Brent Lang Executive Editor When it came time to create the more than 200 mini-skirts, sequined dresses, elegant suits and other outfits that the cast of “Bob Fosse’s Dancin'” hoofs it in, costume designers Reid Bartelme and Harriet Jung faced a big dilemma. They needed to pay tribute to the legendary choreographer’s legacy while still making something of the moment. That meant combing through archival material from Fosse’s many shows, ranging from films like “Kiss Me Kate” and “Cabaret” to his late-period masterpieces such as “Big Deal.” But there was very little to consult when it came to the 1978 original “Dancin'” other than a few grainy videos of a Japanese production and some photos of Willa Kim’s costumes.