As the house deal third party never came forward the Ls felt that this person had skin in the game somehow and was likely responsible for her disappearance and/or a nefarious motive.
SL said she would tell the family all about this 'deal' when things were settled (told her father and spoke 'extensively' about this the night before she went missing and her parents said they wished they had taken things more 'seriously'). Whilst there was no listing for Mr Kipper re: Sturgis' 'books', there may have been a person working with her who was listed legitimately under their own name/as client of Sturgis. JH, H being the name that was another word for Kipper, had been a client in the past, and/or his brother. Yet, very many were Sturgis clients at one time or other, it was a large agency with much reach. Was there any one else she knew socially on the books. No doubt the police looked at the time with this in mind.
This person was boosting her purchasing power and the family apparently thought that there were some strings attached to such a deal. Looking to spend about 100k said one article and it might have been then that Shorrolds was one that was of interest. Poss the idea was to only look at the outside and see if suitable for development before going on to see another property or similar. Poss 'Kipper' was a in joke between SL and this person. This person may well have been JC. Poss Shorrolds was immediately deemed unsuitable so it was merely a quick rendezvous for another destination.
Her parents sold her flat in/by Nov 1986 to a couple who had been extensively negotiating with her prior. There had been two or three abortive attempts to sell the flat and all this would point to a keen interest/urgency re: selling up quickly.
On the BW sighting it's interesting that not only did she run the property agency, was plausible, smart and compelling, but her sighting of SL was on Monday afternoon. In other words, it was AFTER the weekend and the beginning of the week. Less likely to be confused with any other weekday, then. She didn't realise its significance at first but was certainly very sure, saying she saw SL for about 30 seconds plus. She stuck to her guns for some time it seems, she was very sure she'd seen her.
The police visited BW's office and checked her diary and with colleagues (AS the source) to see IF she had actually left when she said she did on this Monday afternoon (BW) and what the time would likely have been. Indeed, she HAD left on Monday afternoon for her apt just as she said she did.
The police later decided she must have been mistaken.