I think you will be surprised
£500 will get you quite a few micro brands around that mark using ETA, seiko and Citizen movements.
Vintage at this price point is a bit of a gamble but if you go for lesser known / defunct makers you can get some interesting watches at this price point.
If it were not for lock down I would happily let you have a look at a few I have as I also live in Ealing.
For £500 I would look at our hosts options first of all vintage looks with good built quality and modern materials.