A letter signed by Rabbi Chaim Kanievsky to strengthen the matter of the obligation to study the laws of the Mikdash "That it hastens redemption ... Soon the Temple will be built and we need priests to work, and certainly a mitzvah for everyone to learn the laws of korbanot ..."
It is possible that even the letter itself (not only the signature) was written by Rabbi Chaim Kanievsky.
[1] p. 15x11 cm. Very good condition.