It's XO bikes. They re-cycle s/h and unclaimed bikes. Apparently, they are the Met's unclaimed bike re-cycler of choice. They are staffed by ex-offenders. It is probably a legit deal.
ETA - And, as you say, given some of the upgrades fitted, it looks like someone loved that bike at some point. https://xobikes.com/product/brompton-black-foldable-bike/
It's XO bikes. They re-cycle s/h and unclaimed bikes. Apparently, they are the Met's unclaimed bike re-cycler of choice. They are staffed by ex-offenders. It is probably a legit deal.
ETA - And, as you say, given some of the upgrades fitted, it looks like someone loved that bike at some point.
https://xobikes.com/product/brompton-black-foldable-bike/