Those may have been in an early version of KOTOR, but it looks a little too bright to be Sleyheron. Too bright, too clean. A 'crime' world like Sleyheron I'd expect to be sprawled with grafitti and bustling with low-lifes of all sorts. Of course, it may just've been before they had a chance to add such things, but my gut tells me 'no'.
It did have a Gammorean in it. I bet Sleheyron got cut was because they couldn't put a star map on it, in KOTOR II I'd like to see a couple of planets you can go to that aren't related with the main plot, rather they have side quests involving those planets. I mean in real life you aren't forbidden from going somewhere just because you don't have any business there.