I've got a couple suggestions if you get into reshaping your saddles... But take these with a grain of salt because I have no actual skills!
I suggest making a radius guide out of cardboard to help you with your bridge slotting. I believe we're working with a 12" radius here, and you can check the cardboard guide against any fret to see if you've got it right.
You can use this guide to site the bottoms of the slots you are cutting - OR- you can also use it on TOP of the strings while they're on the bridge saddles. That's because the growing string gauges from G to B more or less reflect the same radius as the bottom of the slots, if you see what I mean.
Also, I recommend moving the saddles to the edge of the bridge (pickup direction), or securing them some other way so that your filing doesn't pull them back and forth on their mounting screws and rods. No need to add any additional wear to those parts!
On last one: I made nut files out of old strings and a chunk of wood. Brass is fairly soft so I found I could "file" it away using just the strings as abrasives. At least the slot size comes out right that way!
Good luck!
Jimmy J