, tried a bunch of things that didn't really work out, but I did found a backup from ~1 month so with the changes still somewhat fresh in my memory I began yesterday night and today re-adding them and it goes faster that I expected, so atleast there is that. I think I can finish it today with a bit off overwork.
I am lucky this was only the editor code that was damaged, the rest I can re-use.

I however find it really odd how the code got corrupted. It must have happenend in SED but in SED everything looked normal.
Also SED backups are quite worthless, I wonder why JCL didn't put in some system that saves scripts per date (or per week) instead of overwriding everytime since script files aren't that big anyway.