Those are very fine drawings indeed.
What would you like? -A critique of your drawing ablities? Suggestions?:
-You may want to consider using a different drawing utensil... sharpie is for moving boxes, not design drawing.
-Also, you may want to consider using at least an entire peice of 8.5x11 paper, instead of a partial one, that seems to be chewed on by some rabid squirrel. mabye even step it up to 17x11 to really fit in some detail.
-A straight edge might even be in order for these types of drawings...
-To add even more realism consider using a pancil with some shading techinieques such as crosshatching and smudging, it really makes your drawings come to life.
-Mabye even bust out some colored pencils and do some simple renderings with light and color.
-But other than that your well on you way to becoming an artist every bit as good as almost any 9 year old!