I found this weird, too, but it's just one of those deals where you have to suspend disbelief and accept. This is the DARK SHADOWS universe, and what you would imagine happens in our own doesn't necessarily follow suit in theirs.
I, too, thought both Edward and Judith should have recognized Quentin. It was kind of silly that they didn't.
I think Curtis wanted to scare us all with those two hideous faces--and of course, like Josette, Evan needed a hanging eyeball (missing on Quentin).
Considering the lack of time involved, their makeup people did a damned good job, IMHO, in making those two look like their faces had been attacked by an eggbeater.
Love, Robin