One thing I know for sure, it is ULEZ exempt for central London. I checked online and behold I can ride with impunity into the Khan empire! Chatted to City of London officer who was at a check point (traffic lights) and just said I was glad to be heading out for "fresh air" from City fo London. He laughed and basically said have fun. They pulled a scooter for reckless riding. Me fully kitted out sweating like a pig, him t shirt, trackpants, trainers... meh.