The International STa"M Forum

I want to know if some circles will do a siyum sefer torah during the sefirah days. (I understand that there is a debate among Ashkenazim and Sefardim about how one counts the mourning days.)  Here is my conclusion: During the S efirah  days (the days between  Pesach  and  Shavuos ), the Poskim differ if one may perform a siyum sefer torah with dancing and music,  it seems proper to avoid unless there are particular circumstances that preclude the celebration being done at another time. Certainly on  Lag B’Omer  one could make a siyum sefer torah since it is a day of celebration. Likewise a few days prior to  Shavuos  one may make a siyum sefer torah. My reasoning: Shulchan Aruch Harav (Orach Chayim 493:1)  holds that one is not allowed to dance [nor play music] even for the sake of a mitzvah during the sefirah days. (See however  Hiskashrus (vol. 246)  which understands the view of the  Shulchan Aruch Harav  differently to even allow making a siyum sefer torah during the sef

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!