The best firefox extension that captures html, and rewrites links to images as local, is Scrapbook:
https://addons.mozilla.org/en-US/firefox/addon/scrapbook/It's old, and not updated.
But, it saves nicely archived local html versions of web pages with a stable URL based on timestamp. Your repository can be served via dropbox or other way, so you have a link to a stable archived web page.
Use iframe, or explore importing into TW. This is the best I've been able to do in many years of searching.
I have some macros left over from TWC days if you want to see possibilities. You might also explore an old circa 2012 implementation called a "Lightweight Web Archiving" tool that have some instructions and documentation to get you started:
https://drive.google.com/open?id=0B6pMEe8dCtrQYTJmOTkzMzMtYjdlZS00ZDczLWIyNjItNzBkYjc3OTE4NTgyLet me know if this is at all helpful,
//steve.