Brownells has a good selection of ten inch mill files...last one had a handle the one before a padded paddle type handle. Nothing fancy, but these work good and are about $10 (One side is a safe edge.) Call and ask them for these if you cannot find.
One of their three square files in a 8" fine cut is one of my favorites.
Get a tube or two of the file chalk too, no wax in it and it works well.
They used to have (and may still) have a set of flexible/bendable needle files. These are great but a bit pricey at $80, but well worth it. IMHO.
I use quite a bit of good wet dry sandpaper with a wood backing for many things too, cheap and it works well. I like a paint stick as a backer for many areas as I can cut it to shape if I need to...