Lots of threads on WW2Talk about Regiments and the suchlike and a few threads on identifying cap badges but nothing that I can find about how metal cap badges were actually manufactured. Whilst there were quite a lot of manufacturers, with Firmin and Gaunt being the most familiar, and they used two main techniques - die stamped and die cast - that's about the only level of detail we see. There were a range of metals used - white metal, brass aka gilding metal, bronze, blackened, enamelled, etc - and these would have needed different detailed manufacturing processes....but what were those processes? And, of course, there were broached badges, lugged badges, bladed badges and.......
You have kind of answered your own question as far as we can be sure. You would need to contact surviving makers for the industrial processes involved - how much was automated or not. Film archives could be a help. The bigger picture was that once a badge design was approved - by the unit and ultimately the War office, the contract for the bulk of the stock would go to the approved contractor who would produce the master for production and prototypes made for approval - these would be approved and become the 'sealed pattern' and held by the Ministry, unit and manufacturer. This would be the version referred back to if there were any queries. Production would make what was needed with contingency for the forseeable future. During wartime other manufacturers were brought in and a bit of leeway allowed to facilitate their production techniques, materials and processes - sometimes referred to as substitute standard or limited standard and meant to be discarded after the emergency. Whether the unit approved was another matter! There are instances of semi-official or unofficial versions produced for various reasons - extras to the issue for walking out, for the band (not a wartime requirement), sweetheart brooches, for mess staff, etc. These would be produced to varying quality 'in theater', the most basic cast from an impression of an original (as this is an easy excuse for a poor fake make sure you have other evidence AND if you find a dodgy looking badge on a uniform please don't assume it is wrong and bin it to replace it with a 'correct' version - it may be original and help give a context to others*). *There is a cast brass DWR badge which is distinctly 'dodgy' looking. A number arrived on the market in the late 1970's and were written up by a collector as fake - possibly a 'puggaree badge' for native mess staff'. Subsequent investigation found it was commissioned by the 1st Bn. for bandsmen's music pouches for a significant parade in Malta in the late 30's for which there are numerous photos. I trust this is of use.
I read the info in this link a while back: Wehrmacht-Awards.com Quote: "The single most important item in a Third Reich badge* collector’s “bag of tricks” is a working knowledge of period construction and finishing techniques. Most modern reproductions, even the very good ones, fail to capture the subtle nuances of an original piece. With this article, I hope to take some of the mystery out of this subject and arm the beginning collector with enough basic knowledge to serve as a starting point." I suppose that there are many similarities there, but it would be nice too to see a similar body of work (or links to such) compiled on the allies ;-) I'm not sure for example if any of the existing books etc. on the British badges go into much depth on their manufacture, who their designers and manufacturers were, or the makers and techniques of them and their later reproductions or even downright fakes etc. The sheer numbers involved though make it bewildering, even for just the war raised regiments with their brief(er) WW2 careers. I wonder how many WW2 badges are sold with ref. to who their original owners were, or whether buyers prefer pristine - i.e. just out of the box examples - or one's with a history etc. that perhaps have even been battered and/or knocked about through ordinary or even extraordinary use.
