Yes, I have seen the auto-update function as well. But it does not apply to our system because the ESP will create its own AP network to enable communication with a data collection system. So it does not have an Internet connection at all.
To update the firmware we will connect to its AP from our PC and then either use our configuration program to set it up including uploading new firmware if needed.
Or while connected open the webpage 1.2.3.4/firmware and then use the browse button to select the bin file and after that hit the Update button. We have password protected this update page.
I will have a look at just copying over the library to the source dir as you suggest, this will make it simple to version the file(s).
Probably need to copy a few more files though, since ESP8266HTTPUpdateServer has other dependencies.
Thanks!
PS: Is there a way in Sloeber to open an explorer widow on the directory where a library file resides so one can easily get there to copy files? DS