Here is the Press Release for the Ancient Egypt Adventure Set. The first paragraph says:
"Tomy Co., Ltd. (President: Kantaro Tomiyama) is pleased to announce the 42nd anniversary of its release of the railway toy "Plarail". In addition, "Plarail Ancient Egypt Adventure Set", which is the first product concept of a fictitious world, will be on sale from August 9, 2001."
It goes on to describe the set contents and how it plays, and suggests that it will be the first in a series of Time Travel adventure sets.
"Tomy Co., Ltd. (President: Kantaro Tomiyama) is pleased to announce the 42nd anniversary of its release of the railway toy "Plarail". In addition, "Plarail Ancient Egypt Adventure Set", which is the first product concept of a fictitious world, will be on sale from August 9, 2001."
It goes on to describe the set contents and how it plays, and suggests that it will be the first in a series of Time Travel adventure sets.