Or did early Christians ever have have a belief that the gospel was a direct revelation from God to Jesus, kind of like how Muslims believe the quran was dictated by the archangel Gabriel to Mohamed?
Church tradition (as recorded by Eusebius) has Mark the Evangelist being a scribe for Peter, writing down his stories while he was peppered by questions in Rome.
He claimed Matthew wrote the now lost Gospel to the Hebrews.
Palisades claimed the Gospel according to Matthew was a collection of sayings gathered by Matthew.
Likewise Luke and John were supposed to be wriiten by people with the same names.
Note that modern scholarship disagrees, but you were asking about the tradition, so there you go.
In no case has God ever dictated anything to mankind, with the possible exception of the Ten Commandments.
Only fundamentalist churches believe in things like that. Mainstream churches do not, using instead the notion that the sacred texts were inspired in same way, but still written by man and not inerrant.
You may want to ask on r/AcademicBiblical. They might have more expertise.