Would a custom, Jailbroken 3.1 3gs Firmware...

[terrapin]

if I could locate one, if installed using redsn0w, be an easy "fix" for JB the phone? I must be oversimplifying

[Kuntry]

That depends. Are you on 3.0 or 3.0.1 and jailbroken? If so, then yes (but you don't use redsn0w to update only iTunes). If you aren't currently jailbroken on 3.0/3.0.1 then no. I'm sure they're working on a jailbreak for 3.1 official firmware but it may take some time.