Olson's Doll House menu was answering before the quest system had counted your 'talk to Olson' step, so Delivering the Pendulum was never ready to hand in to him. Fixed: talking to Olson now counts the step first, and the hand-in shows in his menu (with the scroll reward choice). LIVE. Re-test: after Grandpa Clock, talk to Olson the Toy Soldier in Ludibrium.

Follow-up: we checked every quest with a 'talk to this NPC' step (576 steps across 281 NPCs) by clicking each NPC the way you would. Nine more steps had the same problem as Olson: Moony in Amoria, Cassandra, Zhen Long and Mr. Jo in Yu Garden, and two stylists (Fabio in Edelstein and Wang Ching Ying). They are all fixed now: clicking an NPC always counts its talk step first, and a stylist with a quest for you now shows the quest next to the salon menu.