I am sorry because I did not worked on your drawings (It would be much faster but I didn't know about)
I based my drawings on 3 main sources as below (I added your Twin Otter now)
BTW checking your drawing I found out that at least there are several identical points as well several completely different parts like the asset, the heigth of the tail, the fuselage (mine is fatter in the rear part).
Anyhow if you consider this drawing coming from yours I'll remove mine.
PS: I added also the original drawing of argentinian one
PPS: your propellers seems strange: it is not a 3-blades one.