Recently I happened across the estate sale of a former MN Zoo employee. I was able to pick up a number of old zoo shirts ranging from the 1980s to more recently. A few of these have a neat little “Conservation” montage of zoo animals and the monorail:
There were also quite a few issues of Minnesota Zoo Magazine from the 1980s. A few of them had monorail-related pieces, including a neat shot of the snowplow in action.
And we even found a monorail ticket from 2008! (Two-sided scan below)
Some of these will probably end up in my mini-museum in the monorail cab.
Saveitforparts 
I so enjoyed my years doing tours on the monorail. I am very happy that you are making a museum of this. I only wish the monorail had stayed at the Minnesota zoo. It was a great loss to them.
There were times when we would joke and say “when we retire we want to go live in one of the train cars.”. Who knows… it might just happen!
Thanks for the thought and work you are putting into this.
Diane Balcom