Surely.. 'Oxford Bags', 'Spencers', 'Bowling Shirts' et al were the fashion when Northern Soul was at its height? Mid 70's period. Basically, everyone was wearing these clothes, not just soulies.
It's just a myth that these are Northern Soul (or 'Soulie') clothes/gear. If you go by the actual records, mainly 60's, early 70's and the fashions the artists wore and the original fans.....then (for me anyway) it has to be 'Ben Sherman', 'Levis'....etc.
Always amuses me when folk not into the scene still think that we wear vests (with patches), Oxfords...and the rest. I suppose they're still regarded as Northern Soul clothes by the masses...