I couldn't help being drawn to the fact that a note written by Albert Einsten in November 1922 that just sold at auction for $1.56 million is on Imperial Hotel letterhead.

Architects know the Imperial Hotel was designed by Frank Lloyd Wright, who boasted about it surviving an earthquake in 1923, the year it opened. Even with those "strong bones," the building was demolished in 1968 to make way for a larger building for the hotel.

A portion of Wright's Imperial Hotel sits in the Meiji Mura Architecture Museum in Nagoya:

But Einstein wrote the note in November 1922, the year before Wright's hotel opened in September 1923. So what building was Einstein staying in, and why does the letterhead look very "Wright"" I'm guessing that Einstein stayed in an annex that Wright designed in 1919 to replace the old Imperial Hotel that was destroyed in a fire that year. The annex opened in May 1920 but then burned down in fires brought on by the 1923 earthquake, the same one that Wright's main hotel survived. Furthermore, with the old hotel gone and Wright's annex in place in 1922, therefore it makes sense that Wright's letterhead (he created many distinctive letterheads) would have been in place already.
If my amateur sleuthing reveals that Einstein stayed in a Wright building and wrote on Wright letterhead, so what" Well, I'm surprised that none of the articles covering the auction mention Wright, although they all, obviously, mention the Imp...