I found what I consider the Holy Grail

[Super]

I never would've considered this to be a preschool train set, maybe slightly older.

I agree with you there. These motorized trains have small parts that can come off easily let alone a battery that could all harm a child too young to know any better. In my opinion the wooden line would be more pre-school safe than these. Maybe this was before the established rules on age appropriate toy ratings.