I've tried to get a couple of them to advertise here but no luck yet.
I can see why the legit ones would want a deposit as I'm sure a lot of guys chicken out at the last minute. At the same time, we all know it's a common scam of non-legit providers just to get easy money.
This site "may" have a bit more credibility than LL:
https://shemalecanada.com/search/city/london