Again, thank you so much to all. I believe I am beginning to understand.
I have ordered the Giandel 2200W 12V inverter. It has a permanent 3-wire connection for higher power-required service that includes a ground connection. It also has a case ground connection and I previously added a chassis ground connection for my old, failed inverter to which I can connect the case ground on the new Giandel. That eliminates any question about how I should connect the new Giandel.
Note: At the same time I added the extra ground connection for the old inverter, I also disconnected the 3 other chassis ground connections (power panel, generator, and ?), cleaned the corrosion and rust, purchased new brass bolts and re-installed those ground connections using liberal amounts of dielectric grease. I think I am good there.
The only remaining problem is installing the on/off switch for connecting the inverter to the RV's AC power panel. I have a marine-grade 1-Off-2 selector switch to use for (1) inverter input to the power panel, or (2) generator input to the power panel. That switch will connect to the power panel through the existing transfer switch (for the Onan generator). That way, shore power and/or inverter/generator power cannot be on at the same time. I will mount that switch next to the generator prime/start/stop/hours control panel so it is difficult to make a mistake on the power input source. The only time that switch will be on the generator connection is when I am starting the genset. Since I have to turn the genset off at the same location, it will be harder for me to leave the 1-Off-2 switch on the generator setting when turning on the inverter. And, even if I did, the inverter power would not go to the power panel.
If I have problems installing the new inverter and the switch, I will ask questions here, of course.
Lastly, I appreciate that for some it may be preferred, safer, more comfortable to install separate GFCI plugs wired directly to the inverter. In my RV layout, that would mean literally removing the permanently mounted TV and built-in microwave every time I wanted to switch from inverter power when boondocking to shore power at an RV park, or vice-versa. That's not viable for me. At my age I can barely lift the microwave into the high built-in location, as it is.
Again my heartfelt thank you to everyone who has contributed to my education and problem-solving.
jesfl