Like Rev said, Cold Steel has quite a few G-10 lockbacks (Tri-Ad lock's pretty much the same) without liners. The American Lawman or Voyager are close in dimensions to the Endura.
Another option would be the Al Mar Eagle Ultralight, it's got a linerless micarta handle and a 4" blade. It's not built to take abuse like the CS folders, but it's super light and very well made (they should upgrade the stell, though).