The seller messaged me back after I asked if he had any history on the engine. He told me that he found the engine & accessories in a box at his father's house after he passed away. It seems he nor his younger siblings knew anything about a box with a toy steam engine! He is guessing someone gave the engine to his dad but no one in the family really knows for sure. While the dad wasn't a collector vintage things, the seller said his dad was a NASA Engineer - so one could see how a friend / colleague could have given it as some kind of a gift.
My mind thinks of some kind of a cool NASA Engineer's x-mas party in the 70s / 80s and it was a White Elephant gift! Wouldn't that be a hoot of a gift LOL!