Wouldn't it have been simpler just to compile up the existing ext2fs user-space tools? I'm sure you could have written a simple program that made use of libext2fs...

Nobody told me libext2fs existed until I was half way through doing this :-) And even if they had, I'm not convinced I could have downloaded it, built it (on a machine I didn't know a lot about), learned how to use it, and written a front end in less than the time it took me to adapt code I already knew all the ins and outs of.