A bit rough.
This is a little tool I wrote to teach myself c64 assembly. It helps designind characters by showing you the numeric value for a pattern you are drawing at the screen.
If I am feeling courageous, it could become a full character editor (allowing you to save and load your characters).
I didn't write the basic launcher, so you have to sys 49152 to launch charedit. Move around with cursor keys, plot/unplot with space. You can quit by pressing "q".