I don't know that "Space: 1999" series, but these are very nice drawings.
But although, as I said, I don't know this series, I am actually quite familiar with the "Eagle Transporter", just under another guise.
When I was a small kid, Polish television ran a series (very visibly done on a shoestring budget) that was about giving basics of mathematics for small children in an entertaining manner. It was called "Przybysze z Matplanety" (Visitors from Math-planet) and was about pair of extraterrestrial aliens (named Sigma and Pi) that were visiting Earth and were making observations of various situations that had simple mathematical connotations (adding, subtracting, basic geommetry etc.).
And it seems that their vehicle was the Eagle - just perhaps slightly repainted, and, I guess, used with complete disregard of copyright/trademark issues (those communists, you know...
)
https://www.youtube.com/watch?v=6W50zWln-e4
https://www.youtube.com/watch?v=qTAgCljjlQo