Norman,
There is also W.D. & S - Dobson & Sons, Ltd. [W.], who are shown as fuze manufacturers. Also, Cossor, [A.C.] who made No. 221 fuzes. WDC supplying the diecasting makes sense, although they are shown a fuze manufacturers(No. 151). Cook Co., (Manchester) Ltd looks good for the assembler. The only Chadwick I have is Cobden Chadwick Ltd., Oldham, which might just justify a superscript 'O'. Neither of which I have listed as fuze manufacturers. I think I have the fuze contracts for WWII, I'll take a look.
Tim
Update
********* Cook & Co had at least one contract for 100,000 No. 119 fuzes, mark and date unknown *********