anode plug, yep $20. at southavenrv.
The old plug must have been out for a while. I thought it maybe 5/8th thread. But looking at southavenrv, it had to be 3/4". I checked at 3 auto part stores for a set of pipe tap loaner tools, nope just bolts. We chased the threads with a 3/4" pipe nipple and wire brush used for cleaning copper fitting for soldering. So I wouldn't have to buy the 3/4 pipe tap at $27. That took a while but it saved me that money. And changing the pressure valve, we should have seen some wires running to the water heater. Only wires I've seen in that area are for the rear trailer lights and the bedside table, not listed on the breaker panel either.

Yep, new phone for christmas and I can't send pictures with it.