Following up.
Leak has stopped. Not by my own doing. Grandpa(89) worked
some "Fels Naptha" bar soap into the pin hole. No leaking yet (+500 miles since soap plug). He said it was a pretty common solution for
plugging pin holes in leaky pans (50 years ago?)

Treating it like a science experiment each time I drive the truck I climb under there with a magnifying glass and look to see if its starting/started to leak...

Purchased JB Weld and have a propane torch,solder and
flux in the truck. Waiting for the soap to run out. Expect today's rain might move things along.