You obviously can't disclose your nodes for others to test or be telling us what you're going to do over clearnet when.
Yet during the time of an outage, you might try to leave the old tor running and - copy over old tor .tor and torrc to a new tor instance, start it and see if it works over the guards. That may point some state jam inside the old tor and a good clearnet path. - run a new tor with no .tor and default torrc and try to telnet to the old guards OR ports over that, then they seem to be up. - put a TransPort in that new default torrc config, put packet filter in front of old tor, hup the new one, see if old tor works over this tor... to point to your clearnet path to the guards being specifically bad to tor. - turn on old tor debug log and see where it is repeatedly stalling.
A script could determine this in a couple minutes.