There are 3 "types" of NAND.
SysNAND = Chip on your 2/3DS mainboard
EmuNAND/RedNAND = just a copy of the sysnand (only difference between them is where the NAND Image starts on SD)
RedNAND
RedNAND places the full NAND image at byte offset 512 on the SD card. The modified firmware hence needs to offset all NAND reads and writes by 512 bytes.
EmuNAND
Calling the NAND image size N, EmuNAND places bytes [512:N-1] of the NAND image at byte offset 512 on the SD card, and bytes [0:511] at byte offset N. The modified firmware needs to make sure that NAND reads/writes to the first 512 bytes are redirected properly, but leaves all other accesses unmodified.
Source:
http://3dbrew.org/wiki/NAND_Redirection
So whenever you copy an emunand or rednand back to your sysnand, it becomes sysnand. It doesn't matter if it was an emu- or a rednand before. It also doesn't matter if it was created with gateway or with emunand9.
AFAIK there is no difference between a emunand cretaed by the GW launcher.dat und the emunand created by emunand9! (emunand created by emunand9 also works with GW).
conclusion: a "GW sysnand" doesn't exist
Why do you want to start classic mode?
Tell us what you want to do.