Great info Jim (AirJimL2), thank you for giving me some details on the history of the design. Also appreciate all the other inputs posted so far...thanks guys!
What got me going on this was not only the modeling link I posted, but at a visit to the Olympic Air Museum in Olympia, WA., I saw this TBM...
http://www.olympicflightmuseum.com/airc ... ry/tbm.htm
...and noticed the unusual back canopy. I wasn't sure if that was just an expedient way to close off the canopy's aft end until a turret could be found and restored, or what. While researching this, I found all kinds of photos of Canadian fire bombers with similar types of aft canopies, as well as other shapes as well. So I'm trying to get an understanding of what was "production" and what were the post-production mods. There appears to be a lot of variety out there. For example, check-out the photos at this link:
http://scalefirebombers.com/index3.html
(on the left menu, select "Fixed-Wing Tankers, Part 2", then again on the left menu at the very bottom, select "TBM/TBF" and scroll through all the great firebird photos)
By the way...that "ScaleFirebombers" site has tons of great post-war warbird photos to look though...kept me busy for hours and hours!