There was a twill Leibertarn jacket with WSS insignia posted on WAF in 2016, which was judged likely authentic, as its insignia was confirmed real, and the printed pattern matched that of known originals. On the other hand, the example that started this thread is printed in a pattern that matches exactly
a present-day commercial pattern, which was once available on Spoonflower (copyrighted by Richard Montgomery). It is still being used to make fashion garments right now, for instance this:
Either this jacket is the grand daddy of the commercial pattern, or, more likely than not, given the other issues that had already been pointed out, it is a relatively recent creation.
It's worth remembering that the original Leibertarn, as well as some of the early Swiss derivatives, were printed using different sized rollers for different colors, causing the latter to overlap at different intervals, virtually eliminating repetitions in their alignment (the exact repeats happen over dozens of yards rather than dozens of inches). Indeed, that was one of the main claims in Leiber's original patent! The modern commercial tribute pattern doesn't have this feature. The fact that the pattern on this jacket matches the Montgomery drawing exactly in terms of color alignment is pretty good evidence that it IS the Montgomery drawing.