Sorry to hear of the continued suffering. Short of buying an expensive panel mount, I don't know any way to make the Artex happy when it wants that Aviation protocol.The saga continues today. I have contacted Artex, Garmin and Aircraft Spruce for information and help. So far no good answers. My situation is complicated by the fact that I live and fly in Alaska and the Feds have all but regulated shipping lithium batteries to/from Alaska, Hawaii and Puerto Rico out of existence. I can't even get small Nikon camera or laptop computer batteries shipped here other than surface.
I believe a standalone GPS receiver that will output in 4800 baud NMEA should be fairly easy to find, and not very expensive, but that means you have to get your ELT reprogrammed. As for shipping, the battery is user replaceable, so perhaps you can remove the battery, and send the unit that way?