Here's a funny bit of info regarding this whole process ...
My Pre Plus had been in Airplane Mode during last night's attempt to activate the Pre 3. I only turned off Airplane Mode after we decided to reactivate the old phone. Pre 3 off the account, Pre Plus back on. Seemingly no issues.
During my drive home, the Pre Plus displays a notification. It is no longer signed into my Palm Profile. Seems another device is currently using it. O.o A few followed prompts and restarts later, the device is reconnected to the profile and most of my info/settings are restored.
Now I am wondering if the Pre 3's inability to connect to my profile was somehow related to the Pre Plus being signed in. If I had completely powered down the Pre Plus, would I have been more successful with the Pre 3? Is there some way to force a device to "sign out" of a profile?
Anyway, the Pre 3 has not yet been doctored with the latest version. But, thanks to roams11 and someone on another forum, I now realize that the 2.2.3 JAR file *is* the executable I need to run rather than a file to be uploaded to the Pre 3. (Silly me).
I have the Verizon 2.2.3 webOS Doctor running. Does the Pre 3 need to be in any specific mode before I connect it to my computer? Cantaffordit has confirmed I don't need to put the device in USB mode. But I'm just wondering if I need to anything beyond flipping the power switch and plugging in the USB cable.
Thanks all for the comments and help to date! I'm very nearly there!