AviatorKLGB. When you say "I fly with FAA typed pilots all of whom could sign me off to get the SIC on my FAA licence" please don't think that a type rating and ATPL allows them to do that. There is more to it than that and if you are not in the US, chances are they cannot do it as that is done under FAA part 135.
What I am saying is that if you are in Europe, an FAA ATPL pilot cannot endorse your FAA certificate for a F2TH (SIC ONLY) Read the regs objectively, and don't listen to a pilot who believes he can do that for you under part 91.