If you haven't checked it out before, Nicholas Rougeux often does these types of modernization conversions for older printed content: https://www.c82.net/

e.g. here's a very beautiful reproduction of Euclid's elements https://www.c82.net/work/euclid

Yes, I'm familiar with his work --- it's very nice, but it's not the on-line and animated/interactive thing I was trying to describe/specify/ask about.