THANK YOU SO MUCH FOR THAT INFO! Really, you pointed me to where I wanted to go but didn't expect to get to so soon.
So, I tried the master reset and the consistent part here is that it will not connect to download the update, just blink blink blink.
Following your instructions (had to install pyserial, for other readers information), close the Arduino IDE Serial Monitor window (apparently gets its own handle to the COM port) and some trouble with my connections, I managed to get the 1.0.5 core written with the #define DEBUG_SETUP. (OH, yeah!)
I found the Arduino IDE Serial Monitor options (none) disappointing so switched to PUTTY to capture the entire serial output.
Adding some more meaningful debug info to the system I found that even though the WiFi is apparently working, after Oak.connect() executes, Oak.waitForConnection() times out and the connection fails. Hence, there is no Particle connect attempt.
I'm now off on a journey of discovery in the bowels of the Oak system to add more debug info in the area where the connection fails. My gut says faulty micro memory somewhere, like a setting isn't taking hold.
A point in the right direction (file) would be great, otherwise, "a huntin I will go".