The overlays that highlight 17th century London features are approximate and derived from:
The hall of the Worshipful Company of Loriners, originally a trade association for makers of metal parts for harnesses, bridles, spurs, and other horse apparel. More on the Loriners at Wikipedia. The location is shown on this 18th century map.
The Loriners, or Lorimers (bit-makers), of London are by reputation an ancient mistery, but they were first incorporated by letters patent of 10 Queen Anne (December 3rd, 1711). Their small hall was at the corner of Basinghall Street in London Wall. The company has no hall now.