I love Ditko as well.
However, I believe it to be a myth that Ditko wanted the Goblin to be revealed as someone other than Norman, as someone the readers didn't even know; besides, this was already done in the Crime Master storyline.
Ditko started sneaking Norman in as early as ASM 23 as a rich business friend of J.J.J., finally introducing him by name in ASM 37.
Ditko made it clear the Goblin had a laboratory and a fairly nice hideout where he'd change back into his secret identity (that was hidden from the reader).
In ASM 37 Ditko reveals Norman to be unscrupulous in his dealings with Mendel Stromm and Ditko shows it was Norman that killed Stromm (but how, since earlier in the story Spidey recognizes that the gunshot that killed Stromm came from outside a second story window; so how could Osborn possibly be that high the air?)
In ASM 38 Norman acts even more suspicious, disguising himself to meet up with underworld figures in order to put a contract out on Spider-Man.
And then there's this - in a 2009 essay Ditko wrote for The Comics, stating:
Now digest this: I knew from Day One, from the first GG story, who the GG would be. I absolutely knew because I planted him in J. Jonah Jameson’s businessmans club, it was where JJJ and the GG could be seen together. I planted them together in other stories where the GG would not appear in costume, action.”
“I wanted JJJ’s and the GG’s lives to mix for later story drama involving more than just the two characters”
“I planted the GG’s son (same distinctive hair style) in the college issues for more dramatic involvement and storyline consequences”
“So how could there be any doubt, dispute, about who the GG had to turn out to be when unmasked?”
First I have heard of that. Makes me wish even more he had penciled the interiors of 39 & 40 being as it was a confrontation he had been a part of setting up for some time.
Well i guess i should be thankful for the runs he did on Spidey and Doc Strange they are respectable runs. Not quite KIrby FF lengthy but long enough that they made their mark for sure.