Forgot to mention I'm running all this on a Mac with Snow Leopard 10.6.8.
Well, I followed John Smith's advice and started with the thread he quoted in his reply to my original post. This led me to a couple of other interesting threads, and I found Gilles Bihan's Converio conversion program for Windows. I contacted Gilles to ask if he had a Mac version and he sent me this link:
for use with Macs. It's in French, but I was able to dicipher it enough to download the free version and run it against my Canon FS300 .MOD files and it worked! It generated .AVI files that successfully loaded into Premier Pro as widescreen clips. Hooray! Thanks, Gilles. M. Biher also offers additional functionality for ten to twenty five Euros. I may go for the upgrade to see if I can convert to MPEG2.
Problem solved for now.
Thanks for the help.