Steve is right - that large image is of a RI Paisley. The earlier MIJs (80s) and the Tokai Pink Paisleys (also mid-'80s) had the closest to the real thing. The silver backing paper (looks like fabric, but that was the old textured wallpaper backing) that Rafa dug up is REALLY close!
I also agree that the lighter, brighter silver would do the trick nicely.
The more recent CIJ runs and the current production Paisleys have a very flat undercoat - I'll take a closer look at a couple this weekend (hopefully!), but it is almost like flat silver paint beneath a white-backed paisley decal...
This is a really cool project!