Thank you all for welcoming me.
I did find a potential coolant leak on the line going to the thermostat. Evidence of leaking at 3 different hose clamps - at the thermostat, and both sides of the piping ell that has the high point coolant system bleed screw. See photo. I’ll cross my fingers and keep an eye on it. I had the air filter off for cleaning and did not get a chance to start it and watch for a leak afterwards.