Hi
There have been various articles / talks / bits of research into Charles Bredgen (there are several spellings of his name) over the years, and I need to refresh my memory as to quite what the present understanding (or lack thereof...) might be. There is also an argument to be made that Grenelle did not exist as factory, but only as a retail outlet (Don French presented a case for that in a talk at a PCC meeting a couple of years ago). If you can email me, I can send you some relevant images / pdfs.
Alan