Google Books is an amazing resource, the result of the online goliath's project to provide search access to all the world's printed literature. In some cases, their collection contains the entire text of books. More often, a table of contents and sample pages are provided. Other times, only small excerpts of text around the search term are offered.
I have only begun to delve through the myriad hits returned for Rabbi Spektor. Have a look for yourself.
Here is a clip from volume one of the book "The Brisker Rav," a biography of HaRav Yitzchok Ze'ev HaLevi Soloveichik, by Rabbi Shimon Yosef Meller, in a section about the response from various important rabbis to a new government regulation that secular subjects must be taught in yeshivas.
I am sure there are others, but this is the first time I have seen a photo of Zvi Hirsch Rabinowitz, the son and successor of Rabbi Spektor in Kovno. At the time of this incident in 1892, Isaac is still living and Zvi is a rabbi (not the chief rabbi) in Vilna.
Walter thought he saw a resemblance of Stan in the photographs of YES. I'm not sure who Zvi looks like.