I became a dritboatman not to run whitewater, but to be an expert steelhead fisherman. I think in the end, I got pretty good at both, but, can say, I once in a while got in a situation that, as they say in the vernacular "would **** your nuts up". I miss those days. My nuts worked OK until prostate surgery.
I have also run the Grand Canyon and drifted the Salmon in Idaho. Don't ask me which part.
I will make a sketch and somehow PM it to you. Included will be a dissertation on Al oar construction (not step by step). Mostly blade dimensions and oar stop placement. I am 79 1/2 years old and my computer skills and running a driftboat skills are not remarkable.
Running a driftboat is a necessity if one wants to be a successful steelhead fisherman. I have seen more than one homemade driftboat, and many were characterized by inappropriate seat placement, inappropriate oarlock placement, etc. incompatible oars. Un less you have run a really sweet handling driftboat thru a fairly rapid rock garden , you really don't know what you're shooting for. This is not intended to be a putdown. If all you want is a rowboat it's a lot less critical.
I am not prepared to offer my drawing skills to the forum at large. I am,however, willing to offer all the free advice to you I can, including a stab at a drawing oars (Al) as I knew them. Keep in mind my oars dated from 1970. My feelings will not be hurt by what you choose to do, but, I do reserve to say "I told you so".
Don't sweat the lack of progress statements. Takes the pressure off me. I appreciate your willingness to share and expose your work to criticism. Not sure I could do the same. Keep on and I'll see what I can come up with.
My oar blades were roughly 20" long by 8" wide. rectangular in shape but with the corners cut off. If you can visualize this we're off to a good start.