1. Who was the Ductile Detective?
The Elongated Man
2. Who was Horn-head?
3. Who was the Pinioned Policeman?
A pinion is the wing of a bird, so the Pinioned Policeman is Hawkman.
4. Who was "Stretcho"?
Stretcho is Reed Richards, aka Mr Fantastic.
5. Who was Goldilocks?
Goldilocks was this fella:
Lots of entrants this week. The Groovy Agent submitted all five correct answers, as did Dan, Jehingr and Michael Rebain. Checking in with four right responses were Mike P, Lito S, and Ralph C. Congratulations to all; you really know your Silver Age Comics!