Sorting blanks isn't *that* horrible. It's a bit daunting at first, but it helps to approach it a little like a jigsaw puzzle.
You should probably ignore the numbers on the bottom, and just keep in mind that all of the keys for a given row will be the same profile. First find the keys that only go in a particular place. Space, mods, and shifts for row 1; Caps, enter, f, and j for row 2; Tab and pipe for row 3; Backspace for row 4. Then find the single unit keys that match those profiles. You can line up keys that you think are the same profile and then try to get eye-level with them to confirm that they've got the same height and slope.
It depends on the exact keys you've got, but usually the row 1 keys will be the most slanted away from you, the row 2 keys will be noticeably less slanted, the row 3 keys will be closer to flat and slightly taller, and the row 4 keys will be by far the flattest and tallest.
Have fun!