Thanks to everyone. Indeed its a sad story ...
I had a look at Cricklewood's website and its ok, but nothing that's worth doing the trip. I used to go to Singapore a lot and there is Sim Lim Tower https://www.simlimtower.sg/ which I always visit when I am there. Something like 8 stories of market stalls selling electronics in all shapes and forms. Some big and branded and in small back-alleys tiny one-man hole-in-the-wall places... I hope they still exist. I haven't been there for 4 years ... I assume that Tottenham area was something like it?
But I will definitely check-out Novelty-automation for some fun. 
Maybe, although Edgware Road was never up to the standard of Asian electronics markets in terms of shear size or selection. Tottenham Court Road (TCR) had always been more end consumer focussed, mostly on AV, then gradually it became more PC & PC component oriented. Only half a dozen shops remain, with most of the store fronts now seemingly fast food chains pandering to the office worker... which is ironic, considering office workers actually working in offices are such a rarity now!
Over the past 30 odd years, they've all been squeezed out by gentrification, ever increasing rents, and Amazon.
I haven't been to Sim Lim Towers for about four or five years, but there were quite a number of empty units on my last visit, and most of it seemed to be more consumer electronics and PC related stuff rather than components.
Akihabara similarly is a shadow of its former self, although there are four or five hard core component/tool/test gear shops I go into every time I'm over there, plus the Radio Center market, which is a bit "Cricklewood" in terms of era. The hard core component shops continue to be very busy: they've kept up with trends, you can pick up modern stuff in there like FPGAs and recent MCUs etc.