The T4 doesn't have Lowrey sounds as such. The T5 does, in Organ World, but you can't copy them. There is the US Organ expansion pack, which has some Lowrey flute/leslie sounds. You can, if you're prepared to do quite a bit of editing, get some way towards the Symphonic Strings sound that the TGS had. And with more editing, you can take some of the really old, plain voices and get something like some of the preset voices from the TGS.
I went back further and created sounds based on an older Lowrey, the GAK-H.
