Oh man. I remember back in the 1990's, there was a company that you could fill in a grid with all the letters in your handwriting (block letters only), mail it to them, and for something like $50 they'd mail you back a floppy disk with a TrueType font of your handwriting a few weeks later.

These days, it occurs to me that with some kind of deep learning, you could probably take a couple dozen pages of someone's cursive, and turn it into a font with thousands of ligatures and variants that would be virtually entirely convincing.