interesting thing about the B30, its shaft seems rather long. It has a bushing to keep the pulley out and it makes that wobbling noise. I looked at Allen's Steam site for Empires (he has two B30's listed) and neither one has this longer shaft. hmm.
Well, maybe it is correct and not modified? I think I spy a longer shaft in this YouTube from
The B30 variations, a symphony to listen and watch to… by @Nuvolari