Jimmy,
The lit'ra'ture says, I think, all models were the same from '41 - '46, maybe 'cept the COEs.
One possible variation would be whether heater was installed - thinkin' there are "knock-outs" for the heater coolant lines. (Mine doesn't have a heater)
Here's a few of my firewall, HOWEVER . . . mine has a fire-engine related accessory that mounts on the passenger side firewall, so I've got holes that others don't. Use 'em if they help.
http://www.me.com/gallery/#100021Hope this helps.
-Michael