Engineering Diamonds

My uncle and grandpa used to work at Engineering Diamonds when it was based in Warwick Row. Mum has been trying to remember where it was exactly and has a memory that it was in a cellar and somewhere near the Pepper Pot Cafe. If you looked down through a window, you could see the men working at the diamond cutting.
as a child, I used to think of them cutting big sparly diamonds for jewellery until grandpa told me that it was for cutting tools, I was very disappointed after that as it seemed so boring and ordinary.
Anyway, can anyone shed any light on the exact whereabouts of this workshop and when they moved?

Their address was 26 Warwick Row
If you look at Google Street View, it shows The Lounge at that address backing on to Sheriffs Orchard

Thanks for the reply MR. I will have to go walkabout next time I am in town and then report back to mum

Anyway, can anyone shed any light on the exact whereabouts of this workshop and when they moved?

Elaine, planning records say it was located in the basement under Number 26 from 1930 to 1960 when the basement was finally taken over by the 'Kung Wa' restaurant.

A friend tells me it was normal for diamond cutting companies to be located in basements under ordinary buildings in city centres.