I haven't seen these before either. The eagle overprints are from the revolutionary period in which there was a lot of turmoil and confusion, so there might be stamps overprinted in such a way, but I would say now that these are fantasy. A bit like all the fancy overprints from end of WW2 Germany.
The railway overprints are almost certainly fakes and are identified as such in the specialized literature.
re: Indonesian overprints ??
I haven't seen these before either. The eagle overprints are from the revolutionary period in which there was a lot of turmoil and confusion, so there might be stamps overprinted in such a way, but I would say now that these are fantasy. A bit like all the fancy overprints from end of WW2 Germany.
The railway overprints are almost certainly fakes and are identified as such in the specialized literature.