These sets were a remarkable bit of engineering for their day and I've wanted one for a very long time. I remember reading your article on the television-in-a-suitcase back when I was in high school studying electronics. I'm an electrical engineer now for a packaging machinery manufacturer.
Steve McVoy at the ETF ended up selling me a Merrill with a restored chassis, but only a dud 15GP22 was available. Steve deserves the credit for the chassis restoration. My focus was on the cabinet and finding a picture tube.
Recently, I received a letter from a guy in Philadelphia who had three NIB 15GP22's. He found them in a storage room of an old technical school. Two of the tubes had gone soft. I bought the only one that still had silver getter flashes. Interestingly enough, the cartons were addressed to the Philco Corporation. I am trying to gather more info on the background of my new picture tube and will pass on anything interesting I discover.
During the second weekend of March, I installed the tube. My heart was racing as I waited for the high-voltage to come up. And then there it was, color! Albeit poorly converged and blotchy.
After repairing the wire-wound cross-purity control and some quick purity and convergence adjustments, I had a pretty decent picture. The color has a deep richness to it. Off-screen photos don't do justice to the picture quality.
Cape Cod, MA