The nice thing about a drawing, is that the knife CAN be made exactly to the drawing. People do it in all kinds of different fields everyday. It's a blue print.....of a knife. I take my lines, measurements, everything off the drawing. If you're careful, it HAS to come out like the drawing.
My point is, especially on a project like this one with so many parts, don't even start it if you're drawing isn't right. There have been times where I've left a drawing sit on the table for days and days because something didn't look 'right'. Everytime I walked by it, I'd stop, stare, turn it end for end and upside down. Looking at it from every angle until I figured out was was throwing my eye. More often than not, it's a VERY subtle change that makes all the difference in the world.
I'm not the best drawer in the world. Not even close. In fact I'd say it's more difficult and takes longer for me to draw something than it takes me to forge and grind the blade or shape the handle. Blades are pretty easy for most people. I don't see too many blades that are badly misshapen. It's handle angles and shapes where a lot of people get off track. I can forge and grind a blade to shape pretty easily, really. After I have that, I need to know that the handle will flow with the blade shape and be properly proportioned.
Once you have your blade to shape and exact size, trace it out and then fit a handle that's pleasing visually to it. Then it pretty much has to turn out like your drawing, if you're careful. For drawing, get a set of french curves. If you get a handle that you like and want to use again, make a pattern and save it. I have a whole drawer full of blade and handle patterns, and patterns for guards and fittings. They can really help lock a design in.
If it doesn't look right on paper, it most likely won't look right on a finished knife. If it looks good on paper, nice flow and proportions and lines, then chances are, it will look right when the knife is finished. Of course, small subtle tweaks are often possible and even necessary but the general lines and proportions can stay the same as your drawing.