I copied the source to a local html file. Then I removed some icon urls and replaced the broken ones in the format bar with text (link, image, download). I also searched the code for http & image links, finding only the above link in the footer.
I put the modified template in my Downloads folder and bookmarked it in FF. When you save, it writes a copy to the downloads folder and does not overwrite. Works!
Just last week I was searching for "modify local text file in browser."
Because Nash writes an html file I can use tampermonkey to manipulate content locally. Mostly, I use Nash to write notes while browsing and stash them in a NashNotes directory.
When copy-pasting from web to Nash, it generally does a very good job of keeping the formatting. I find this particularly helpful when moving reports to local.