1.5 and 1.2.1 are working in different ways...
1.5 launcher is creating new data packs and the game automaticly read from them, after you installed Revival 1.5b1, check the game's /data/ inventory you will find 4 files:
the first two are files from 1.5b mod pack, and the other two are what the launcher extracted from TCv4. and if you installed an optional mod 1.5b contained, there would be two more files, and the optional modificatons would be there.
and, since it is working in a different way, you cannot directly modificate a table with reanimator and save it, because the game does not read from it. but also it is much more easier to modificate with 1.5b, you can unpack the 1.5b mod pack, the tables are already uncooked in .txt format, find the table you want to modify, open it with Excel, do your modification, save it, repack the mod pack and name it as you wish, like "wizzbang.mod.zip", install it with 1.5b launcher, you would get what you want.