I asked before I took my camera out. He said it was ok as long as I didn't reach into the layout when taking pictures (as not to damage anything). I guess that the fear of damage (not of having photos of the layout all over the Internet) is what made George forbid photography.
With good reason, I guess. I live in Florida, and went back "home" to Maine several years ago. While in Bangor, I called Mr Sellios and asked if I could visit. He said he was open the following Saturday, so I drove down to Peabody on the only Saturday he was open during my trip. I'm not usually that lucky with timing!
Anyway, to get to my point, while I was standing back taking pictures with my Nikon, another visitor was off to my left at the end of the layout nearest the front windows. He leaned waaaay over the layout with his camera to take a shot over the town square above the underground station, and dropped his camera. He chipped off a corner of one of the pavement squares where the concrete had section joints, but didn't hit any vehicles, structures or figures.
Did make an obvious white plaster chip which was a real eye-catcher. George walked over to see the damage, got a paintbrush and a jar of paint the color of grimy cement and touched it up. Within a few seconds it was almost indistinguishable. Lucky the damage was so slight. I never heard Mr Sellios say anything to him, but the guy left shortly after that.
I thoroughly enjoyed the visit and all the details. I suspect I actually noticed way less than half of what was there, but the overall effect of a depression era urban area was stunning.