Perfect ! A very nice place for short or longer stays : brand new, cosy, in an area which is both very quiet and convenient : Central London easy to reach ; St Pancras at 10 min on the Northern line; close to Belsize Park underground station (a 10 min walk); groceries at 3 min walking distance on a village-kind place.
Brian is very welcoming, available for questions and discreet.
We had a very nice time in London and the apartment was part of it !