Yup. Some times looking at the "first to check" may be the correct action:
Here is what I found when disconnecting the battery cables at the battery end of the car:
Battery Bolts
Battery cable positive end - what is this happening here -why all the pitting in the metal?
Other end of the same cable
Cable to ground at the battery needed attention too.
The ground cable at the Engine (corner - cyl 6) was not as bad but still showed signs of corrosion.
All of these connections were cleaned back to good metal and added DiElectric.
Will give the trial a week or two to see if this was the fix... feels much better to have clean contacts.
Will need to check the connections at the starter when next under the car.