I've often teased my "green screen" clients that I could rewrite all their software to run in a browser. (It's not really that much of a stretch.)
What would really be impressive on OP's webpage would be F keys and Esc that worked as advertised in the text. It's really not that hard to coopt them from the browser.
Well, it did; the similarities between the web sans AJAX (which we just called "the web" back then!) and 3270 were noticed by the early Netscape developers too.
I wonder if someone has the original pixel maps floating around.