Interesting. I took the train to the summit in 2003. Mt Washington in NH has a tiny little PO booth at the summit building. I don't call it the 'eating joint' like the 1921 PC. I've never taken the time to send myself a letter back home though. The reason is that there are too many distractions. It can be a nerve wracking drive up, there's the amazing views, the need to eat, etc. I've been up there at least 10 times but never 'slowed down' enough to talk to the people at the booth and buy anything. Maybe next time?