Sorry to bring the topic up this long after the initial post-
For what its worth though, Saddleback does in fact use Chrome tanned leather (I think they make it themselves now, but I could be wrong). However, I think oil-tanned is chrome-tanned leather that has been essentially finished again with oil. Not sure about the process exactly, but yeah.
I just picked up a side of Springfield Leather's utility side. Its fantastic, and easily comparable to Saddleback's look. I would recommend that if you do order it (and its pretty darn reasonable too, I think I payed 80-100 for the side, off hand), definitely specify a color preference. They'll give you what they have (a downside), but they're pretty good people to work with.