I'll assume that the diminished chord in question is a passing chord or variation of the Bm leading to the next chord change in which case, yes, it's a B diminished. If it is being used in the context of an actual chord change, then you'd not only be changing key, but the eventual name of the chord might depend on the chords that follow. In this instance, (in my very limited knowledge) the name is up for grabs without having more information.
Replacement Wide Range Humbuckers and modifications. Yes, we've got the CuNiFe