Recently I saw on the internet a lot stamps of Ecuador, including 2 airmail triangle stamps of which you said they were totally unknown to you.
Well, if you don't know nothing while you are so close to the source, I do know less.
We can now add a fourth stamp with a value of 10 sucres to the 3 you did publice before on September 2, 2017 (TRES AÉREOS NO EMITIDOS DEL ECUADOR).
The printing is not bad, but inferior to the emitted stamps from the 1930's years, therefore I think they are fake (or even cinderellas?).
I assume they were made directly after the first airmail stamps (1929) with the trainstamps from 908 as example. Maybe after 1935 when the first airmail stamp of 2 sucres came out.