Do tell, The gearing appears to be non standard. Is it a conversion cog on a Sturmey three speed? I built a commuter, in the early eighties, using a Raleigh Record frame set. I had obtained an old Cyclo- Benelux three speed cog that fit on a Sturmey Archer AW hub. It allowed me to shift into a low gear at a complete standstill. It was a really nice commuting bike. It was stolen from me in Philadelphia. I 've been looking for a conversion cog like that ever since.