Henry
I think you may have misunderstood me, your uncles house pr business was quite close to Great King St on Hockley Hill. In the late 60's they demolished some of the property in that area to make way for a new flyover that was needed, and as there is no listing in my copy of 1973 Kelly's Trade directory. Its almost certain that your uncles property fell victim to this bit of urban renewal.
If you are able to obtain a plot number and plan, then when I go to get your photo, I will take a look if anything remains of the premises.
Phil