The tik (silver case for sephardi torah) was made too small. It cannot be fixed & cost $15,000. Is it mutar to cut 1/2″ off the top & bottom margins?
Provided that there is enough kelaf on both sides (the shiur is four thumbwidths on the bottom, and three at the top), it is permitted to cut the kelaf for this purpose. See Mishnah Berurah 334, to se’if 20. It is not permitted to cut the kelaf for no reason, but according to the conclusion of the Mishnah Berurah, it is permitted to cut the kelaf for a new Sefer Torah, which has not yet been studied from.