There are 4 emplacements on the Mudchute farm in the Isle of Dogs,3 are used as animal pens for the farm and the the 4th one has been set up as it was during WW2.
Thanks for all that effort CL1, it is just what I was after, my local gun emplacements were pretty much identical to those shown - the iron doors had all gone though from the internal stores. Just need to try and find out if the large concrete building at mine ( 'E' on my marked up os plan) was as I suspect the main ammunition store. Thanks again.