The 109 is officially a "Bf", but "Me" is often used.
Apparently the Seattle 109E is not a russian recovery, but rather based on parts (main spar, 1 and a half wing and landing gear) dug up in France in 1988, at least according to
http://www.preservedaxisaircraft.com.
Thats why it wears the Battle of Britain JG 51 paint job, but basically it is a new aircraft.
Stupid is that every preserved P-40C HAS to be painted as AVG aircraft! The P-40Cs are almost always russian recoveries and some had a perfectly preserved markings with red stars, and some were even flown by russian aces! Yet that history was erased for the sake of that AVG worshipping.
The 262s use US engines, I think the same as in some early US aircraft. The Jumo 004 is not inherently dangerous, but the wartime engines of that type have a very short life and low tolerances due to shortage of precious materials.
A Jumo 004 with the right alloys would have been a good engine, but constructing a engine from scratch is above the head of most warbird projects.
DB 605s are readily available, it seems, but other axis aero engines are not.
Btw, I don't suppose the FW-190D-13 has ever flown since restoration. It is airworthy, but it is a singulary aircraft in so many ways that no one sane would risk to crash it. It is the only 190 Dora in any displayable shape (one other is a very slow restoration project in germany) and the most original german WW2 aircraft, with most original parts still there.
Not to mention that the Jumo 213 engine is irreplacable as well.