@ look 171, I haven't encountered a road bike from the era of that Trek or earlier that won't accept 28c tires. I have 3 bonded Vitus frames from the 80's through the early 90's. All of them take 28c tires no problem.
My 1979 Guerciotti is on 28c, no problem. While there aren't many available, I am sure I could get 30c tires on there, and possibly 32c.
I considered trying out these 30c tires, but don't know enough about them to drop the coin:
Strada Bianca PRO
This place is a great source for tires and items to turn your old road bike or old thin steel MTB into a mixed surface machine:
https://www.compasscycle.com/product-category/components/tires/
Further, having used the Compass tires, I know they are made by Panaracer. The Panaracer Gravel king tires are virtually identical to what Compass offers, but are less cost.
https://www.thebikesmiths.com/products/panaracer-gravelking-700c?variant=44543411474&gclid=EAIaIQobChMI7pm8mYuA2wIVhFqGCh198g6AEAQYBCAB EgLQovD_BwE
These are lightweight and high threadcount fast rolling folding clincher tires that are designed for more rugged use than racing tires.
