Rabbi Dov Bernard Revel - Rabbi Revel probably received ordination from Yeshivas Knesses Beis Yitzchak-Kaminetz which was founded in Slobodka in 1897

Respectfully, I would suggest evidence Rabbi Revel learned and was ordained at 16 at Yeshivas Knesses Beis Yitzchak-Kaminetz https://en.wikipedia.org/wiki/Yeshivas_Knesses_Beis_Yitzchak-Kaminetz
as many have pointed out he couldn’t studied at the Kovno Kollel https://en.wikipedia.org/wiki/Kovno_Kollel , because by 1891 (when Revel was 6) I have read that it was closed down and people like Rabbi Blazer mentioned by many of his bio had moved onto "Slabodka Kollel" https://en.wikipedia.org/wiki/Yeshivas_Knesses_Yisrael_(Slabodka) (but the leaders there were sometimes referred to as “from Kovno”, as in “Rabbi Yitzchak Elchanan Spector from Kovno” -hence the errors some make in assumption it was the “Kovno Kollel” (rather than 2 successor Yeshivas in Slobadka).
see https://en.wikipedia.org/wiki/Yitzchak_Blazer but in 1897 (When Revel was 12) there was a breakaway from the "Slobadka Kollel" and Knesses_Beis_Yitzchak-Kaminetz https://en.wikipedia.org/wiki/Yeshivas_Knesses_Beis_Yitzchak-Kaminetz which i think would be the closest Hashkafic match, no? [based on the evidence Revel was ordained in about 1901 at about age 16 this seems the most likely place he would of been learning based on his outlook and later interaction with mentors such as Rabbi Boruch Ber Leibowitz who would head that Yeshiva in 1904.]