Turns out macintoshgarden.org switched to https for a few days but then reverted when it was causing some hitches, but TenFourFox would automatically try to connect to a nonexistent https site even if you typed http in the address bar.
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After purging my history of all macintoshgarden links and clearing out all macintoshgarden cookies, I still couldn't get TFF to connect to http. Finally this was the solution to my problems:
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"That's done it. I edited the SiteSecurityServiceState.txt in my Firefox profile, deleting the macintoshgarden entry. Now I'm back in."
Kind of ironic the solution was in a thread I temporarily couldn't access in TFF, but all is well now.