Optimus V and S ROMs do not work on Optimus T.
Optimus S Roms should work on V, but you would have to make sure in that section of development here. I am pretty sure I heard something about scripts that will change V Roms to work on S, but being a T user I am not certain.
For Optimus T, you have to use Optimus One ROMs.
So far as I know, the difference in those models is a bit more than just the radio. I don't know enough to say specifically why, but just take a look at the sections here. You can see there is a reason Optimus One and Optimus V have differing ROMS and development sections here.
If you want to be 100% certain, I know Optimus S Roms are here: http://forums.androidcentral.com/lg-...ng-roms-hacks/