i have attached a scan of an undated photocard of V.A. Semyonov as Blue Bird in THE SLEEPING BEAUTY - he would appear to be wearing the costume that Nijinska claims was revised for Nijinsky.
it's a recent acquisition but also timely because there is about to be - or has it happened already? - a celebration held by the Bolshoi Ballet in honor of the 100th birthday of Marina Timofeyevna Semyonova - who was once married to V.A.S.
(i have scanned this photo at slightly larger than usual resolution to show the detailing of the costume.)

This might be silly, but were wigs commonly used in ballets during this time? Doesn't the Mariinsky still use wigs in their ballets so that everyone is the same?

wigs remain variously in use at the Maryinsky, but also in other European companies, the Royal Ballet is another case in point.
UK members can address this tradition with more authority.