Indy, Very nice design. I have a suggestion for you. Place a piece of tracing paper over the top of this drawing.. Using a .03 or at the largest a .05 black pen and trace the drawing only on the side of the line you are going to cut on. You will find that it makes a huge difference. Remember that your cuts are going to be much smaller than your drawn line or wider if you roll your tool.
Take a look down the right side of this sample. Look what happens to the size of the object if you cut on the outside of the line or the inside of the same side line. remember the cut becomes part of the background so you have to decide beforehand which you are drawing and cutting -the object or the negative space. both have their uses
You are at the point in your drawing that you need to consider these factors to take that next step up the ladder. I do all my drawing on tracing paper. that way as I refine the picture I can just add another sheet and go from there keeping what I like and throwing out what I don't like. My drawing table mounts in my ball vise and my light box even fits on this 10 x 12 drawing board. -Fred