"Some of the equipment to make these high quality elaborate replicas can be as expensive as those used. by genuine production factories themselves!"
My (educated) guess is some of the replica cases/bracelets/dials etc. are made in the same facilities that make cases/bracelets/dials etc. for genuine brands and the machines are programmed to make extremely accurate replicas during late hours etc.
Example...Swatch and many other swiss brands have cases/dials/bracelets etc. made in China, I remember about ten years ago when eBay was flooded with steel 'Tissot' quartz chronographs, new with B/P for about one third of the genuine watch price.
The quick and easy way to tell the replica from a genuine watch was the price. I had one, ETA movement and all, it even had a 'Tissot' owner's manual and 'History Book' with it.
Here is a genuine example in case anyone sees one for sale...
https://www.youtube.com/watch?v=oJwoiiu0kYE
There was more than one grade of these replica chronos, mine must have been from the top of the heap.
China, Taiwan, Vietnam and a few other countries have factories that can make any of the watch cases etc. as accurate to genuine as the guy paying for them wants them to be.
Take the USA for example:
No doubt a first class job shop could duplicate a rolex case to 100% perfection.
Q...Why has it not been done on a large scale, that we know of?
A...Because labor here is many times higher than China/Taiwan etc. so it is not worthwhile. It is also more risky because RUSA would chase them down one way or another as soon as word got out. No one can keep a good secret.
RWC does not have much clout in China/Taiwan/Vnam.
This brings me back to the genuine rolex replacement '444' cases...a detailed Yuki 5512-5513 case (for example) from a few years ago with a '444' serial number would more than likely pass for genuine. I saw a few at a watch show with genuine movements, case tubes/crowns/dials/hands and no doubt they would pass as genuine.
Q...How do I know they were not genuine?
A...I knew the guy who had them.
I used a Yuki case for an example because other than a few small details, they are the spittin' image of a '444' case.