That looks sweet!
I picked up a Banzai Run with an XR7 playfield a couple of years ago and had no clue until I got it home... and neither did the seller!
I had an old beater example and was buying this new one as an upgrade. The seller's basement was pretty dark but I was amazed at how bright the whites and other colors were on the playfield. The cab was undamaged but had some planking so we agreed to a price that I thought was more than fair.
When I got it home and compared the two side by side I knew something was really different. The new one had zero UV damage and looked clearcoated while the other was old and yellowed with a dull surface. Sure enough, I raise the playfield and looked at the edge and there were the XR7 markings.
I know Pat Lawlor was quoted at Expo a few years back stating that he only sent less than 10 BR playfields out for testing with this new coating, but I wonder about the accuracy of that. It seems to me that I've seen more than a few pop up on the various forums over the years. If we assume 2-3 of the XR7 playfields went into the prototypes and no more than 7 or so were left over and eventually thrown into production games (like mine), and also assuming all of those 7 survived, something doesn't add up... it seems like there are a lot more. I think I've counted at least 3 or 4 of us in this small thread that have one.
If anyone has any more info/corrections to the story I'd love to hear it. In any case, it's an interesting piece of pinball history. Both the game and the development of XR7/Diamondplate.