The chips are all painted with Vallejo acrylic by hand. here's a tutorial online: http://www.track-link.net/gallery/3014
Yeah, i'm pretty familiar with 131 at the Bovington museum. The kit came with the decals for it, but I didn't want to make that one since it's got a history that everyone knows and I could be more artistic with my weathering, (since I like to keep my "real" models as accurate as possible). 112 is from the same Battalion in Tunisia, but I couldn't find any info on it's history. I'm also waiting for the Dragon Late Tiger which should be out soon. If it's anything like the early that they released, it'll be awesome.
If you're interested, here's a site that has a video of the #131 in action, from the Bovington Museum's Tank Day Festival, or whatever it's called.. heh. It loads kinda slow for me, but it's cool to watch if you're a Tiger nerd like I am.
http://www.tigerwerk.com/