The International STa"M Forum

Sefarim that are only ever used for one reading tend to wear out in that area. On Shabbos Chol Hamoed, we noticed some faded letters in the maftir sefer (not our maftir, but the one for Shavuos a little earlier on the amud.) While repairing them on Sunday,  I found many other letters beginning to peel. I also found out that the last yeriah in Pinchas and the first one in Mattos had already been replaced once due to this problem and I was fixing the new yerios. Constantly rolling over the same portion for decades takes its toll. Gabbaim can easily prevent that from happening by rotating their shul's Sifrei Torah. This is a cross post from my own blog where I wrote about it at greater length.

This year I am doing a siyum on Chol hamoed. It's the fifth time I have done a siyum on Chol Hamoed . If the outline of the remaining letters is written before Yom Tov and the siyum involves just filling in letters,it is permitted to do so on chol hamoed because such work is not considered maaseh uman. It is for this reason that it is not uncommon for a siyum to occur on chol hamoed. My question is, if something goes wrong i.e. there is a smudge or mistake that needs to be repaired during the siyum process - and the skill needed to fix it is masseh uman  - ie we are not just filling in letters anymore, this is a proper tikkun - what is the din? Thankfully it has never happened to me, but I was wondering what happens in such a case and if anyone has experience in this matter. A gut Moed!