How things have changed! Yes Mike, that's the place. I've just had a look on Google streetview and can tell you a bit more. The low building attached to it (out of sight to the left in your picture) was the main showroom, which could only be accessed via the shop itself by walking through the workshop. Approximately a third of the ceiling space in the showroom was taken up by what I can only describe as a suspended floor, which was used to store wheels. I can't see any sign of it in streetview, but between the shop and the showroom was another doorway, a narrow alley between the two buildings, where the staff used to put their own bikes.
The top storey of the shop wasn't accessible from the business - it was, in my day, a separate flat that was let to a lady by the name of Val. The building on the far right of your picture was a carpet warehouse - 'May's Carpets'.
Trying hard to remember some of the brands we sold - in the bog-standard 'complete' category all I can remember are Dawes and Falcon, and we had the franchise for some weird Dutch / Japanese brand called something like Koga Miyata. The more specialist frames were Holdsworth (Reynolds 531 tubing) and Alan (aluminium). Raleigh were despised - mainly due to their using a different size thread on all their components, 26 tpi if I remember correctly, instead of the standard 24.
In those days the best components were Campagnolo - Gran Turismo being the bargain-bucket variety, followed by Record and the horrendously expensive Super Record. Campag also made such delights as little pots of white grease that cost three times as much as other brands. Shimano was sneered at in those enlightened times, but their chainsets weren't really that bad. Their hubs were definitely useless - I can remember a training companion (who later turned pro) shattering his on a semi-regular basis on various hills. Cinelli made some lovely handlebars, my choice being Cinelli 65's. Mavic rims were sought after, and the best tubular tyres were Wollber ('Wobblers', as we called them).