For sure it is not a B front wheel !
Might be still the B-front axle used in an alternative wheel. That would still allow the “bolt on” situation.
Main differentiator is the number of disc screws (4 vs. 6) and number of cover screws (2 vs. 3)
That construction with threaded axle both sides and large nuts, which are clamped below fork tubes is typical for the Bs (not for CSRs / LTDs) !