According to this site, the bonus track on Affenstunde (“Train Through Time”) is from the Messa di Orfeo (1999) sessions. The bonus tracks on In den Gärten Pharaos (“Kha-White Structures I & II”) are of indeterminate provenance, although someone on the internet has speculated that they may actually be from around 1970/71. The tracks can be found on YT.
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