I think the reason why there have been so few successful replications is due to the amount of knowledge it would take to engineer the VIC coil and driving circuitry, not to mention the resources.
We have almost all the info and specs on the circuits and the 5 coil vic but it's still not easy to replicate. And even then we know it took 10 of these units just to power the small 50HP buggy engine.
Stan Meyer began his work in the mid 1970s and died in 1998. Over 20 years of work and he was still in the research and development phase! Just before he died he secured funding to build a research and development center. After all that work he still had not begun to sell retrofit kits.
In the WFC news release issue # 8 the following statement is made:
Meyer has been working on the hydrogen fracturing process technology since 1980 at a cost of about 1.6 million.
That's is a huge amount of money that he spent on just one of many of the parts of his technology.
All the money and time Stan Meyer spent on his inventions should be enough to understand that although the theory is simple, replication is an entirely different game.
As smart as he seemed he did not do it all on his own. He had many people working with and for him. He cleared a way for many others by showing that it is possible but his 20+ year effort shows that it's not an easy task...