I had to do that back then when I first released it. The 1SLW and 1K03 firmwares are both the same only name is changed. I've checked what was all the fuzz about the 1K02, 1K03 and 1SLW firmware for 1802.
And it seems to be newer one then 1K00 originaly inside M1912 drives. I don't know of a way to flash this inside the drive. I've posted it here and on my new Toshiba firmwares page here. Found it shortly after and by my suprise it's already region free (RPC-1). Didn't know it exists for it, but was I wrong.
Got an email with a poor dad whos kid crashed the tray in DVD unit inside the KiSS so he bought a new M1912 model. O What will you need to make it region free
