I got this running -- it was pretty simple to change a couple files in the
boot drive. But I found that it wasn't easy to just connect via a web browser -- you have to configure your laptop to connect properly to the Pi's network, which isn't easy for everyone.
Instead, i'm going to try to get the Pi to produce a WiFi hotspot, called "Microscope" (for this application) which you connect to and it auto-directs you to the microscope page.
Then as a next step, if you still need internet access, it's apparently possible for a 2nd wifi interface on the Pi to connect in turn to another wifi network. I want to make it possible to configure that connection from the hotspot welcome page... !!! Meta, but it could be pretty seamless once it works.
https://howtoraspberrypi.com/create-a-wi-fi-hotspot-in-less-than-10-minutes-with-pi-raspberry/ and also https://frillip.com/using-your-raspberry-pi-3-as-a-wifi-access-point-with-hostapd/