I'd wager all they need to do is get some proper CSS happening and they can visually change things without intrusively changing the HTML content itself. The may need to strip away some deprecated attributes for HTML elements, and add class attributes, but that's about it.

In my case, there is a definite nostalgic bias. I would have used the site near the start of my university studies in 1996. That said, I think there is a case for leaving it as-is. Many sites are designed to be accessible and palatable to students today, so there is some merit to maintaining the original style in case it addresses the needs of people who are not well served by modern sensibilities.

I love it because it loads quickly and isn't more complicated then it needs to be.

I'd argue that using all those images and maps instead of svgs probably makes it load slower and is more complicated than it could be.

some centering would be nice