Well, of course: I do. In fact, that is the point precisely. See: it is not a birth record I am interested in (that is the Piano Atlas), but rather the current piano population and its location.
How many Bechsteins are there in Columbus, Ohio? I know of several, two of which happen to be from the 1870-1880 decade. If I were ever to plan a rebuild, I would love to know whether there are other similar pianos that I can use as a model, or which may be going to be rebuilt more or less at the same time.
Where in the USA are all the Irmler pianos? I suspect there are a bunch in Maryland, DC and Virginia, because Pianocraft carried them for a while and did wonders with them. I also suspect that all people that have Irmler pianos would have some other things in common (be bold and unassuming, comfortable with diversity, and probably with a taste to sweet-sounding music (for me it was the Albeniz-Godowsky tango that did it).
I find it very relevant to figure out where all those pianos are. What do you think?