Finally got my MSL!!!
Win7 Professional 64 bit, Administrator account activated and used.
All files downloaded from links on this forum except 7zip which I already had.
All programs launched using right click --> Run as Administrator from either the actual .exe file, or shortcut to it on desktop - none from the Start menu.
Swapped USB ports a couple of times
Uninstalled and reinstalled drivers.
Tries #1 and #3 had large files when zipped (as per WhisperPntr's reference) but nothing at the suggested hex offset. Tries #2, 4, and 5 had small .zip files, and also nothing.
Try #6 had a large zip file, and at the hex offset it ALMOST looked like the right data (instead of a chain of 6 numbers, there was a chain of 3 numbers, a letter, and 2 numbers. Some of the surrounding data looked ALMOST like WP's example. That gave me the confidence to run it one more time.
Try #7, large .zip, went to the hex offset 07496A80, and there was a 6 digit number (3 of which matched try #6's result). Dialed the diagnostic number, entered it in, and it worked!
Also found at the following locations:
063DA370/063DA380 (wraps on two lines)
0B903880
0B910490/0B9104A0
0B910CB0
0B910DC0
Thanks to everyone whose previous experiences helped guide me.